<html><head><META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>MySQL Connector/J Documentation</title><meta content="DocBook XSL Stylesheets V1.60.1" name="generator"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="book" lang="en"><div class="titlepage"><div><div><h1 class="title"><a name="N10001"></a>MySQL Connector/J Documentation</h1></div><div><div class="author"><h3 class="author"><span class="firstname">Mark</span> <span class="surname">Matthews</span></h3></div></div><div><p class="copyright">Copyright &copy; 2004, 2005 MySQL AB</p></div><div><div class="legalnotice"><p>This manual is NOT distributed under a GPL style license. Use of
      the manual is subject to the following terms: <div class="itemizedlist"><ul type="disc"><li><p>Conversion to other formats is allowed, but the actual
            content may not be altered or edited in any way.</p></li><li><p>You may create a printed copy for your own personal
            use.</p></li><li><p>For all other uses, such as selling printed copies or using
            (parts of) the manual in another publication, prior written
            agreement from MySQL AB is required.</p></li></ul></div> Please email docs@mysql.com for more information or if
      you are interested in doing a translation.</p><p>MySQL and the MySQL logo are (registered) trademarks of MySQL AB.
      Other trademarks and registered trademarks referred to in this manual
      are the property of their respective owners, and are used for
      identification purposes only.</p></div></div></div><div></div><hr></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt>1. <a href="#cj-developing-applications">Developing Applications with MySQL and Java using
    Connector/J</a></dt><dd><dl><dt>1.1. <a href="#cj-what-is">Introduction to JDBC Development</a></dt><dd><dl><dt>1.1.1. <a href="#cj-basic-jdbc">Basic JDBC concepts</a></dt><dt>1.1.2. <a href="#cj-advanced-concepts">Advanced JDBC Concepts</a></dt></dl></dd><dt>1.2. <a href="#cj-installing">Installing Connector/J</a></dt><dd><dl><dt>1.2.1. <a href="#cj-system-requirements">Required Software Versions</a></dt><dt>1.2.2. <a href="#cj-upgrading">Upgrading from an Older Version</a></dt></dl></dd><dt>1.3. <a href="#cj-jdbc-reference">JDBC Reference</a></dt><dd><dl><dt>1.3.1. <a href="#cj-configuration-properties">Driver/Datasource Class Names, URL Syntax and Configuration
        Properties for Connector/J</a></dt><dt>1.3.2. <a href="#cj-implementation-notes">JDBC API Implementation Notes</a></dt><dt>1.3.3. <a href="#cj-type-conversions">Java, JDBC and MySQL Types</a></dt><dt>1.3.4. <a href="#cj-character-sets">Using Character Sets and Unicode</a></dt><dt>1.3.5. <a href="#cj-using-ssl">Connecting Securely Using SSL</a></dt><dt>1.3.6. <a href="#cj-replication-connection">Using Master/Slave Replication with
        ReplicationConnection</a></dt></dl></dd><dt>1.4. <a href="#cj-j2ee">Using Connector/J with J2EE and Other Java Frameworks</a></dt><dd><dl><dt>1.4.1. <a href="#cj-general-j2ee-concepts">General J2EE Concepts</a></dt><dt>1.4.2. <a href="#cj-tomcat-config">Using Connector/J with Tomcat</a></dt><dt>1.4.3. <a href="#cj-jboss-config">Using Connector/J with JBoss</a></dt></dl></dd><dt>1.5. <a href="#cj-troubleshooting">Diagnosing Connector/J Problems</a></dt><dd><dl><dt>1.5.1. <a href="#cj-faq">Common Problems and Solutions</a></dt><dt>1.5.2. <a href="#cj-reporting-bugs">How to Report Bugs or Problems</a></dt></dl></dd><dt>1.6. <a href="#cj-changelog">Changelog</a></dt></dl></dd></dl></div><div class="list-of-tables"><p><b>List of Tables</b></p><dl><dt>1.1. <a href="#N1025C">Connection Properties</a></dt><dt>1.2. <a href="#N10713">Conversion Table</a></dt><dt>1.3. <a href="#N1073D">MySQL Types to Java Types for ResultSet.getObject()</a></dt><dt>1.4. <a href="#N10886">MySQL to Java Encoding Name Translations</a></dt></dl></div><div class="list-of-examples"><p><b>List of Examples</b></p><dl><dt>1.1. <a href="#N10064">Obtaining a Connection From the DriverManager</a></dt><dt>1.2. <a href="#N1007E">Using java.sql.Statement to Execute a SELECT Query</a></dt><dt>1.3. <a href="#N100A8">Stored Procedure Example</a></dt><dt>1.4. <a href="#N100C0">Using Connection.prepareCall()</a></dt><dt>1.5. <a href="#N100E7">Registering Output Parameters</a></dt><dt>1.6. <a href="#N100F8">Setting CallableStatement Input Parameters</a></dt><dt>1.7. <a href="#N1011C">Retrieving Results and Output Parameter
                  Values</a></dt><dt>1.8. <a href="#N1012D">Retrieving AUTO_INCREMENT Column Values using
              Statement.getGeneratedKeys()</a></dt><dt>1.9. <a href="#N10133">Retrieving AUTO_INCREMENT Column Values using 'SELECT
              LAST_INSERT_ID()'</a></dt><dt>1.10. <a href="#N10139">Retrieving AUTO_INCREMENT Column Values in Updatable
              ResultSets</a></dt><dt>1.11. <a href="#N10181">Setting the CLASSPATH Under UNIX</a></dt><dt>1.12. <a href="#N109EF">Using a Connection Pool with a J2EE Application
              Server</a></dt><dt>1.13. <a href="#N10A89">Example of
                  transaction with retry logic</a></dt></dl></div><div class="chapter" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="cj-developing-applications"></a>Chapter&nbsp;1.&nbsp;Developing Applications with MySQL and Java using
    Connector/J</h2></div></div><div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt>1.1. <a href="#cj-what-is">Introduction to JDBC Development</a></dt><dd><dl><dt>1.1.1. <a href="#cj-basic-jdbc">Basic JDBC concepts</a></dt><dt>1.1.2. <a href="#cj-advanced-concepts">Advanced JDBC Concepts</a></dt></dl></dd><dt>1.2. <a href="#cj-installing">Installing Connector/J</a></dt><dd><dl><dt>1.2.1. <a href="#cj-system-requirements">Required Software Versions</a></dt><dt>1.2.2. <a href="#cj-upgrading">Upgrading from an Older Version</a></dt></dl></dd><dt>1.3. <a href="#cj-jdbc-reference">JDBC Reference</a></dt><dd><dl><dt>1.3.1. <a href="#cj-configuration-properties">Driver/Datasource Class Names, URL Syntax and Configuration
        Properties for Connector/J</a></dt><dt>1.3.2. <a href="#cj-implementation-notes">JDBC API Implementation Notes</a></dt><dt>1.3.3. <a href="#cj-type-conversions">Java, JDBC and MySQL Types</a></dt><dt>1.3.4. <a href="#cj-character-sets">Using Character Sets and Unicode</a></dt><dt>1.3.5. <a href="#cj-using-ssl">Connecting Securely Using SSL</a></dt><dt>1.3.6. <a href="#cj-replication-connection">Using Master/Slave Replication with
        ReplicationConnection</a></dt></dl></dd><dt>1.4. <a href="#cj-j2ee">Using Connector/J with J2EE and Other Java Frameworks</a></dt><dd><dl><dt>1.4.1. <a href="#cj-general-j2ee-concepts">General J2EE Concepts</a></dt><dt>1.4.2. <a href="#cj-tomcat-config">Using Connector/J with Tomcat</a></dt><dt>1.4.3. <a href="#cj-jboss-config">Using Connector/J with JBoss</a></dt></dl></dd><dt>1.5. <a href="#cj-troubleshooting">Diagnosing Connector/J Problems</a></dt><dd><dl><dt>1.5.1. <a href="#cj-faq">Common Problems and Solutions</a></dt><dt>1.5.2. <a href="#cj-reporting-bugs">How to Report Bugs or Problems</a></dt></dl></dd><dt>1.6. <a href="#cj-changelog">Changelog</a></dt></dl></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="cj-what-is"></a>1.1.&nbsp;Introduction to JDBC Development</h2></div></div><div></div></div><p>MySQL provides connectivity for client applications developed in
      the Java programming language via a JDBC driver, which is called MySQL
      Connector/J.</p><p>MySQL Connector/J is a JDBC-3.0 "Type 4" driver, which means that
      is is pure Java, implements version 3.0 of the JDBC specification, and
      communicates directly with the MySQL server using the MySQL
      protocol.</p><p>This document is arranged for a beginning JDBC developer. If you
      are already experienced with using JDBC, you might consider starting
      with the section "<a href="#cj-installing" title="1.2.&nbsp;Installing Connector/J">Installing
      Connector/J</a>".</p><p>While JDBC is useful by itself, we would hope that if you are not
      familiar with JDBC that after reading the first few chapters of this
      manual, that you would avoid using "naked" JDBC for all but the most
      trivial problems and consider using one of the popular persistence
      frameworks such as <a href="http://www.hibernate.org/" target="_top">Hibernate</a> , <a href="http://www.springframework.org/" target="_top">Spring's JDBC templates</a> or
      <a href="http://www.ibatis.com/common/sqlmaps.html" target="_top">Ibatis SQL
      Maps</a> to do the majority of repetitive work and heavier lifting
      that is sometimes required with JDBC.</p><p>This chapter is not designed to be a complete JDBC tutorial. If
      you need more information about using JDBC you might be interested in
      the following online tutorials that are more in-depth than the
      information presented here:</p><p><div class="itemizedlist"><ul type="disc"><li><p><a href="http://java.sun.com/docs/books/tutorial/jdbc/basics/index.html" target="_top">JDBC
            Basics </a>- A tutorial from Sun covering beginner topics in
            JDBC</p></li><li><p><a href="http://java.sun.com/developer/onlineTraining/Database/JDBCShortCourse/index.html" target="_top">JDBC
            Short Course</a> - A more in-depth tutorial from Sun and
            JGuru</p></li></ul></div></p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="cj-basic-jdbc"></a>1.1.1.&nbsp;Basic JDBC concepts</h3></div></div><div></div></div><p></p><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="cj-connect-with-drivermanager"></a>1.1.1.1.&nbsp;Connecting to MySQL using the DriverManager Interface</h4></div></div><div></div></div><p>When you are using JDBC outside of an application server, the
          DriverManager class manages the establishment of Connections.</p><p>The DriverManager needs to be told which JDBC drivers it
          should try to make Connections with. The easiest way to do this is
          to use Class.forName() on the class that implements the
          java.sql.Driver interface. With MySQL Connector/J, the name of this
          class is com.mysql.jdbc.Driver. With this method, you could use an
          external configuration file to supply the driver class name and
          driver parameters to use when connecting to a database.</p><p>The following section of Java code shows how you might
          register MySQL Connector/J from the main() method of your
          application:<pre class="programlisting">import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

// Notice, do not import com.mysql.jdbc.*
// or you will have problems!

public class LoadDriver {
    public static void main(String[] args) {
        try {
            // The newInstance() call is a work around for some
            // broken Java implementations

            Class.forName("com.mysql.jdbc.Driver").newInstance();
        } catch (Exception ex) {
            // handle the error
        }
}</pre></p><p>After the driver has been registered with the DriverManager,
          you can obtain a Connection instance that is connected to a
          particular database by calling DriverManager.getConnection():</p><div class="example"><a name="N10064"></a><p class="title"><b>Example&nbsp;1.1.&nbsp;Obtaining a Connection From the DriverManager</b></p><p>This example shows how you can obtain a Connection instance
            from the DriverManager. There are a few different signatures for
            the getConnection() method. You should see the API documentation
            that comes with your JDK for more specific information on how to
            use them. <pre class="programlisting">
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

    ... try {
            Connection conn = DriverManager.getConnection("jdbc:mysql://localhost/test?user=monty&amp;password=greatsqldb");

            // Do something with the Connection

           ....
        } catch (SQLException ex) {
            // handle any errors
            System.out.println("SQLException: " + ex.getMessage());
            System.out.println("SQLState: " + ex.getSQLState());
            System.out.println("VendorError: " + ex.getErrorCode());
        }
</pre></p><p>Once a Connection is established, it can be used to create
            Statements and PreparedStatements, as well as retrieve metadata
            about the database. This is explained in the following
            sections.</p></div></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="cj-using-statements"></a>1.1.1.2.&nbsp;Using Statements to Execute SQL</h4></div></div><div></div></div><p>Statements allow you to execute basic SQL queries and retrieve
          the results through the ResultSet class which is described
          later.</p><p>To create a Statement instance, you call the createStatement()
          method on the Connection object you have retrieved via one of the
          DriverManager.getConnection() or DataSource.getConnection() methods
          described earlier.</p><p>Once you have a Statement instance, you can execute a SELECT
          query by calling the executeQuery(String) method with the SQL you
          want to use.</p><p>To update data in the database use the executeUpdate(String
          SQL) method. This method returns the number of rows affected by the
          update statement.</p><p>If you don't know ahead of time whether the SQL statement will
          be a SELECT or an UPDATE/INSERT, then you can use the execute(String
          SQL) method. This method will return true if the SQL query was a
          SELECT, or false if an UPDATE/INSERT/DELETE query. If the query was
          a SELECT query, you can retrieve the results by calling the
          getResultSet() method. If the query was an UPDATE/INSERT/DELETE
          query, you can retrieve the affected rows count by calling
          getUpdateCount() on the Statement instance.</p><div class="example"><a name="N1007E"></a><p class="title"><b>Example&nbsp;1.2.&nbsp;Using java.sql.Statement to Execute a SELECT Query</b></p><pre class="programlisting">// assume conn is an already created JDBC connection
Statement stmt = null;
ResultSet rs = null;

try {
    stmt = conn.createStatement();
    rs = stmt.executeQuery("SELECT foo FROM bar");

    // or alternatively, if you don't know ahead of time that
    // the query will be a SELECT...

    if (stmt.execute("SELECT foo FROM bar")) {
        rs = stmt.getResultSet();
    }

    // Now do something with the ResultSet ....
} finally {
    // it is a good idea to release
    // resources in a finally{} block
    // in reverse-order of their creation
    // if they are no-longer needed

    if (rs != null) {
        try {
            rs.close();
        } catch (SQLException sqlEx) { // ignore }

        rs = null;
    }

    if (stmt != null) {
        try {
            stmt.close();
        } catch (SQLException sqlEx) { // ignore }

        stmt = null;
    }
}</pre></div></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="cj-using-callable-statements"></a>1.1.1.3.&nbsp;Using CallableStatements to Execute Stored Procedures</h4></div></div><div></div></div><p>Starting with MySQL server version 5.0 when used with
          Connector/J 3.1.1 or newer, the
          <tt class="classname">java.sql.CallableStatement</tt> interface is fully
          implemented with the exception of the
          <tt class="function">getParameterMetaData()</tt> method.</p><p>MySQL's stored procedure syntax is documented in the "<a href="http://www.mysql.com/doc/en/Stored_Procedures.html" target="_top">Stored
          Procedures and Functions</a>" section of the MySQL Reference
          Manual.</p><p>Connector/J exposes stored procedure functionality through
          JDBC's <tt class="classname">CallableStatement</tt> interface.</p><p>The following example shows a stored procedure that returns
          the value of <tt class="varname">inOutParam</tt> incremented by 1, and the
          string passed in via <tt class="varname">inputParam</tt> as a
          <tt class="classname">ResultSet</tt>:<div class="example"><a name="N100A8"></a><p class="title"><b>Example&nbsp;1.3.&nbsp;Stored Procedure Example</b></p><pre class="programlisting">CREATE PROCEDURE demoSp(IN inputParam VARCHAR(255), INOUT inOutParam INT)
BEGIN
    DECLARE z INT;
    SET z = inOutParam + 1;
    SET inOutParam = z;

    SELECT inputParam;

    SELECT CONCAT('zyxw', inputParam);
END</pre></div></p><p>To use the <tt class="function">demoSp</tt> procedure with
          Connector/J, follow these steps:</p><div class="orderedlist"><ol type="1"><li><p>Prepare the callable statement by using
              <tt class="function">Connection.prepareCall()</tt>.</p><p>Notice that you have to use JDBC escape syntax, and that
              the parentheses surrounding the parameter placeholders are not
              optional:</p><div class="example"><a name="N100C0"></a><p class="title"><b>Example&nbsp;1.4.&nbsp;Using Connection.prepareCall()</b></p><pre class="programlisting">import java.sql.CallableStatement;

...

    //
    // Prepare a call to the stored procedure 'demoSp'
    // with two parameters
    //
    // Notice the use of JDBC-escape syntax ({call ...})
    //

    CallableStatement cStmt = conn.prepareCall("{call demoSp(?, ?)}");



    cStmt.setString(1, "abcdefg");</pre></div><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p><tt class="function">Connection.prepareCall()</tt> is an
                expensive method, due to the metadata retrieval that the
                driver performs to support output parameters. For performance
                reasons, you should try to minimize unnecessary calls to
                <tt class="function">Connection.prepareCall()</tt> by reusing
                <tt class="classname">CallableStatement</tt> instances in your
                code.</p></div></li><li><p>Register the output parameters (if any exist)</p><p>To retrieve the values of output parameters (parameters
              specified as <tt class="literal">OUT</tt> or <tt class="literal">INOUT</tt>
              when you created the stored procedure), JDBC requires that they
              be specified before statement execution using the various
              <tt class="function">registerOutputParameter()</tt> methods in the
              <tt class="classname">CallableStatement</tt> interface:<div class="example"><a name="N100E7"></a><p class="title"><b>Example&nbsp;1.5.&nbsp;Registering Output Parameters</b></p><pre class="programlisting">import java.sql.Types;

...
    //
    // Connector/J supports both named and indexed
    // output parameters. You can register output
    // parameters using either method, as well
    // as retrieve output parameters using either
    // method, regardless of what method was
    // used to register them.
    //
    // The following examples show how to use
    // the various methods of registering
    // output parameters (you should of course
    // use only one registration per parameter).
    //

    //
    // Registers the second parameter as output
    //

    cStmt.registerOutParameter(2);

    //
    // Registers the second parameter as output, and
    // uses the type 'INTEGER' for values returned from
    // getObject()
    //

    cStmt.registerOutParameter(2, Types.INTEGER);

    //
    // Registers the named parameter 'inOutParam'
    //

    cStmt.registerOutParameter("inOutParam");

    //
    // Registers the named parameter 'inOutParam', and
    // uses the type 'INTEGER' for values returned from
    // getObject()
    //

    cStmt.registerOutParameter("inOutParam", Types.INTEGER);

...</pre></div></p></li><li><p>Set the input parameters (if any exist)</p><p>Input and in/out parameters are set as for
              <tt class="classname">PreparedStatement</tt> objects. However,
              <tt class="classname">CallableStatement</tt> also supports setting
              parameters by name:<div class="example"><a name="N100F8"></a><p class="title"><b>Example&nbsp;1.6.&nbsp;Setting CallableStatement Input Parameters</b></p><pre class="programlisting">...

    //
    // Set a parameter by index
    //

    cStmt.setString(1, "abcdefg");

    //
    // Alternatively, set a parameter using
    // the parameter name
    //

    cStmt.setString("inputParameter", "abcdefg");

    //
    // Set the 'in/out' parameter using an index
    //

    cStmt.setInt(2, 1);

    //
    // Alternatively, set the 'in/out' parameter
    // by name
    //

    cStmt.setInt("inOutParam", 1);

...</pre></div></p></li><li><p>Execute the <tt class="classname">CallableStatement</tt>, and
              retrieve any result sets or output parameters.</p><p>While <tt class="classname">CallableStatement</tt> supports
              calling any of the <tt class="classname">Statement</tt> execute
              methods (<tt class="function">executeUpdate()</tt>,
              <tt class="function">executeQuery()</tt> or
              <tt class="function">execute()</tt>), the most flexible method to
              call is <tt class="function">execute()</tt>, as you do not need to
              know ahead of time if the stored procedure returns result
              sets:<div class="example"><a name="N1011C"></a><p class="title"><b>Example&nbsp;1.7.&nbsp;Retrieving Results and Output Parameter
                  Values</b></p><pre class="programlisting">...

    boolean hadResults = cStmt.execute();

    //
    // Process all returned result sets
    //

    while (hadResults) {
        ResultSet rs = cStmt.getResultSet();

        // process result set
        ...

        hadResults = cStmt.getMoreResults();
    }

    //
    // Retrieve output parameters
    //
    // Connector/J supports both index-based and
    // name-based retrieval
    //

    int outputValue = cStmt.getInt(1); // index-based

    outputValue = cStmt.getInt("inOutParam"); // name-based

...</pre></div></p></li></ol></div></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="cj-advanced-concepts"></a>1.1.2.&nbsp;Advanced JDBC Concepts</h3></div></div><div></div></div><p></p><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="cj-retrieve-autoinc"></a>1.1.2.1.&nbsp;Retrieving AUTO_INCREMENT Column Values</h4></div></div><div></div></div><p>Before version 3.0 of the JDBC API, there was no standard way
          of retrieving key values from databases that supported 'auto
          increment' or identity columns. With older JDBC drivers for MySQL,
          you could always use a MySQL- specific method on the Statement
          interface, or issue the query 'SELECT LAST_INSERT_ID()' after
          issuing an 'INSERT' to a table that had an AUTO_INCREMENT key. Using
          the MySQL-specific method call isn't portable, and issuing a
          'SELECT' to get the AUTO_INCREMENT key's value requires another
          round- trip to the database, which isn't as efficient as possible.
          The following code snippets demonstrate the three different ways to
          retrieve AUTO_INCREMENT values. First, we demonstrate the use of the
          new JDBC-3.0 method 'getGeneratedKeys()' which is now the preferred
          method to use if you need to retrieve AUTO_INCREMENT keys and have
          access to JDBC-3.0. The second example shows how you can retrieve
          the same value using a standard 'SELECT LAST_INSERT_ID()' query. The
          final example shows how updatable result sets can retrieve the
          AUTO_INCREMENT value when using the method 'insertRow()'. <div class="example"><a name="N1012D"></a><p class="title"><b>Example&nbsp;1.8.&nbsp;Retrieving AUTO_INCREMENT Column Values using
              Statement.getGeneratedKeys()</b></p><pre class="programlisting">   Statement stmt = null;
   ResultSet rs = null;

   try {

    //
    // Create a Statement instance that we can use for
    // 'normal' result sets assuming you have a
    // Connection 'conn' to a MySQL database already
    // available

    stmt = conn.createStatement(java.sql.ResultSet.TYPE_FORWARD_ONLY,
                                java.sql.ResultSet.CONCUR_UPDATABLE);

    //
    // Issue the DDL queries for the table for this example
    //

    stmt.executeUpdate("DROP TABLE IF EXISTS autoIncTutorial");
    stmt.executeUpdate(
            "CREATE TABLE autoIncTutorial ("
            + "priKey INT NOT NULL AUTO_INCREMENT, "
            + "dataField VARCHAR(64), PRIMARY KEY (priKey))");

    //
    // Insert one row that will generate an AUTO INCREMENT
    // key in the 'priKey' field
    //

    stmt.executeUpdate(
            "INSERT INTO autoIncTutorial (dataField) "
            + "values ('Can I Get the Auto Increment Field?')",
            Statement.RETURN_GENERATED_KEYS);

    //
    // Example of using Statement.getGeneratedKeys()
    // to retrieve the value of an auto-increment
    // value
    //

    int autoIncKeyFromApi = -1;

    rs = stmt.getGeneratedKeys();

    if (rs.next()) {
        autoIncKeyFromApi = rs.getInt(1);
    } else {

        // throw an exception from here
    }

    rs.close();

    rs = null;

    System.out.println("Key returned from getGeneratedKeys():"
        + autoIncKeyFromApi);
} finally {

    if (rs != null) {
        try {
            rs.close();
        } catch (SQLException ex) {
            // ignore
        }
    }

    if (stmt != null) {
        try {
            stmt.close();
        } catch (SQLException ex) {
            // ignore
        }
    }
}
</pre></div><div class="example"><a name="N10133"></a><p class="title"><b>Example&nbsp;1.9.&nbsp;Retrieving AUTO_INCREMENT Column Values using 'SELECT
              LAST_INSERT_ID()'</b></p><pre class="programlisting">   Statement stmt = null;
   ResultSet rs = null;

   try {

    //
    // Create a Statement instance that we can use for
    // 'normal' result sets.

    stmt = conn.createStatement();

    //
    // Issue the DDL queries for the table for this example
    //

    stmt.executeUpdate("DROP TABLE IF EXISTS autoIncTutorial");
    stmt.executeUpdate(
            "CREATE TABLE autoIncTutorial ("
            + "priKey INT NOT NULL AUTO_INCREMENT, "
            + "dataField VARCHAR(64), PRIMARY KEY (priKey))");

    //
    // Insert one row that will generate an AUTO INCREMENT
    // key in the 'priKey' field
    //

    stmt.executeUpdate(
            "INSERT INTO autoIncTutorial (dataField) "
            + "values ('Can I Get the Auto Increment Field?')");

    //
    // Use the MySQL LAST_INSERT_ID()
    // function to do the same thing as getGeneratedKeys()
    //

    int autoIncKeyFromFunc = -1;
    rs = stmt.executeQuery("SELECT LAST_INSERT_ID()");

    if (rs.next()) {
        autoIncKeyFromFunc = rs.getInt(1);
    } else {
        // throw an exception from here
    }

    rs.close();

    System.out.println("Key returned from " + "'SELECT LAST_INSERT_ID()': "
        + autoIncKeyFromFunc);

} finally {

    if (rs != null) {
        try {
            rs.close();
        } catch (SQLException ex) {
            // ignore
        }
    }

    if (stmt != null) {
        try {
            stmt.close();
        } catch (SQLException ex) {
            // ignore
        }
    }
}
   </pre></div><div class="example"><a name="N10139"></a><p class="title"><b>Example&nbsp;1.10.&nbsp;Retrieving AUTO_INCREMENT Column Values in Updatable
              ResultSets</b></p><pre class="programlisting">   Statement stmt = null;
   ResultSet rs = null;

   try {

    //
    // Create a Statement instance that we can use for
    // 'normal' result sets as well as an 'updatable'
    // one, assuming you have a Connection 'conn' to
    // a MySQL database already available
    //

    stmt = conn.createStatement(java.sql.ResultSet.TYPE_FORWARD_ONLY,
                                java.sql.ResultSet.CONCUR_UPDATABLE);

    //
    // Issue the DDL queries for the table for this example
    //

    stmt.executeUpdate("DROP TABLE IF EXISTS autoIncTutorial");
    stmt.executeUpdate(
            "CREATE TABLE autoIncTutorial ("
            + "priKey INT NOT NULL AUTO_INCREMENT, "
            + "dataField VARCHAR(64), PRIMARY KEY (priKey))");

    //
    // Example of retrieving an AUTO INCREMENT key
    // from an updatable result set
    //

    rs = stmt.executeQuery("SELECT priKey, dataField "
       + "FROM autoIncTutorial");

    rs.moveToInsertRow();

    rs.updateString("dataField", "AUTO INCREMENT here?");
    rs.insertRow();

    //
    // the driver adds rows at the end
    //

    rs.last();

    //
    // We should now be on the row we just inserted
    //

    int autoIncKeyFromRS = rs.getInt("priKey");

    rs.close();

    rs = null;

    System.out.println("Key returned for inserted row: "
        + autoIncKeyFromRS);

} finally {

    if (rs != null) {
        try {
            rs.close();
        } catch (SQLException ex) {
            // ignore
        }
    }

    if (stmt != null) {
        try {
            stmt.close();
        } catch (SQLException ex) {
            // ignore
        }
    }
}


   </pre></div> When you run the example code above, you should get the
          following output: Key returned from getGeneratedKeys(): 1 Key
          returned from 'SELECT LAST_INSERT_ID()': 1 Key returned for inserted
          row: 2 You should be aware, that at times, it can be tricky to use
          the 'SELECT LAST_INSERT_ID()' query, as that function's value is
          scoped to a connection. So, if some other query happens on the same
          connection, the value will be overwritten. On the other hand, the
          'getGeneratedKeys()' method is scoped by the Statement instance, so
          it can be used even if other queries happen on the same connection,
          but not on the same Statement instance.</p></div></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="cj-installing"></a>1.2.&nbsp;Installing Connector/J</h2></div></div><div></div></div><p></p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="cj-system-requirements"></a>1.2.1.&nbsp;Required Software Versions</h3></div></div><div></div></div><p></p><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="cj-supported-java-versions"></a>1.2.1.1.&nbsp;Java Versions Supported</h4></div></div><div></div></div><p>MySQL Connector/J supports Java-2 JVMs, including JDK-1.2.x,
          JDK-1.3.x, JDK-1.4.x and JDK-1.5.x, and requires JDK-1.4.x or newer
          to compile (but not run). MySQL Connector/J does not support
          JDK-1.1.x or JDK-1.0.x</p><p>Because of the implementation of java.sql.Savepoint,
          Connector/J 3.1.0 and newer will not run on JDKs older than 1.4
          unless the class verifier is turned off (-Xverify:none), as the
          class verifier will try to load the class definition for
          java.sql.Savepoint even though it is not accessed by the driver
          unless you actually use savepoint functionality.</p><p>Caching functionality provided by Connector/J 3.1.0 or newer
          is also not available on JVMs older than 1.4.x, as it relies on
          <tt class="classname">java.util.LinkedHashMap</tt> which was first
          available in JDK-1.4.0.</p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="cj-supported-mysql-versions"></a>1.2.1.2.&nbsp;MySQL Server Version Guidelines</h4></div></div><div></div></div><p>MySQL Connector/J supports all known MySQL server versions.
          Some features (foreign keys, updatable result sets) require more
          recent versions of MySQL to operate.</p><p>When connecting to MySQL server version 4.1 or newer, it is
          best to use MySQL Connector/J version 3.1, as it has full support
          for features in the newer versions of the server, including Unicode
          characters, views, stored procedures and server-side prepared
          statements.</p><p>While Connector/J version 3.0 will connect to MySQL server,
          version 4.1 or newer, and implements Unicode characters and the new
          authorization mechanism, Connector/J 3.0 will not be updated to
          support new features in current and future server versions.</p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="cj-classpath"></a>1.2.1.3.&nbsp;Installing the Driver and Configuring the CLASSPATH</h4></div></div><div></div></div><p>MySQL Connector/J is distributed as a .zip or .tar.gz archive
          containing the sources, the class files a class-file only "binary"
          .jar archive named
          "<tt class="filename">mysql-connector-java-[version]-bin.jar</tt>", and
          starting with Connector/J 3.1.8 a "debug" build of the driver in a
          file named
          "<tt class="filename">mysql-connector-java-[version]-bin-g.jar</tt>".</p><p>Starting with Connector/J 3.1.9, we don't ship the .class
          files "unbundled", they are only available in the JAR archives that
          ship with the driver.</p><p>You should not use the "debug" build of the driver unless
          instructed do do so when reporting a problem or bug to MySQL AB, as
          it is not designed to be run in production environments, and will
          have adverse performance impact when used. The debug binary also
          depends on the Aspect/J runtime library, which is located in the
          <tt class="filename">src/lib/aspectjrt.jar</tt> file that comes with the
          Connector/J distribution.</p><p>You will need to use the appropriate gui or command-line
          utility to un-archive the distribution (for example, WinZip for the
          .zip archive, and "tar" for the .tar.gz archive). Because there are
          potentially long filenames in the distribution, we use the GNU tar
          archive format. You will need to use GNU tar (or an application that
          understands the GNU tar archive format) to unpack the .tar.gz
          variant of the distribution.</p><p>Once you have extracted the distribution archive, you can
          install the driver by placing mysql-connector-java-[version]-bin.jar
          in your classpath, either by adding the FULL path to it to your
          CLASSPATH enviornment variable, or by directly specifying it with
          the commandline switch -cp when starting your JVM</p><p>If you are going to use the driver with the JDBC
          DriverManager, you would use "com.mysql.jdbc.Driver" as the class
          that implements java.sql.Driver.</p><div class="example"><a name="N10181"></a><p class="title"><b>Example&nbsp;1.11.&nbsp;Setting the CLASSPATH Under UNIX</b></p><p>The following command works for 'csh' under UNIX:</p><pre class="screen">$ setenv CLASSPATH /path/to/mysql-connector-java-[version]-bin.jar:$CLASSPATH</pre></div><p>The above command can be added to the appropriate startup file
          for the login shell to make MySQL Connector/J available to all Java
          applications.</p><p>If you want to use MySQL Connector/J with an application
          server such as Tomcat or JBoss, you will have to read your vendor's
          documentation for more information on how to configure third-party
          class libraries, as most application servers ignore the CLASSPATH
          environment variable. This document does contain configuration
          examples for some J2EE application servers in the section named
          "<a href="#cj-j2ee" title="1.4.&nbsp;Using Connector/J with J2EE and Other Java Frameworks">Using Connector/J with J2EE and Other Java
          Frameworks</a>", however the authoritative source for JDBC
          connection pool configuration information for your particular
          application server is the documentation for that application
          server.</p><p>If you are developing servlets and/or JSPs, and your
          application server is J2EE-compliant, you can put the driver's .jar
          file in the WEB-INF/lib subdirectory of your webapp, as this is a
          standard location for third party class libraries in J2EE web
          applications.</p><p>You can also use the MysqlDataSource or
          MysqlConnectionPoolDataSource classes in the
          com.mysql.jdbc.jdbc2.optional package, if your J2EE application
          server supports or requires them. The various MysqlDataSource
          classes support the following parameters (through standard "set"
          mutators):</p><div class="itemizedlist"><ul type="disc"><li><p>user</p></li><li><p>password</p></li><li><p>serverName (see the previous section about fail-over
              hosts)</p></li><li><p>databaseName</p></li><li><p>port</p></li></ul></div></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="cj-upgrading"></a>1.2.2.&nbsp;Upgrading from an Older Version</h3></div></div><div></div></div><p>MySQL AB tries to keep the upgrade process as easy as possible,
        however as is the case with any software, sometimes changes need to be
        made in new versions to support new features, improve existing
        functionality, or comply with new standards.</p><p>This section has information about what users who are upgrading
        from one version of Connector/J to another (or to a new version of the
        MySQL server, with respect to JDBC functionality) should be aware
        of.</p><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="cj-upgrading-3-0-to-3-1"></a>1.2.2.1.&nbsp;Upgrading from MySQL Connector/J 3.0 to 3.1</h4></div></div><div></div></div><p>Connector/J 3.1 is designed to be backwards-compatible with
          Connector/J 3.0 as much as possible. Major changes are isolated to
          new functionality exposed in MySQL-4.1 and newer, which includes
          Unicode character sets, server-side prepared statements, SQLState
          codes returned in error messages by the server and various
          performance enhancements that can be enabled or disabled via
          configuration properties.</p><div class="itemizedlist"><ul type="disc"><li><p>Unicode Character Sets - See the next section, as well as
              the "Character Sets" section in the server manual for
              information on this new feature of MySQL. If you have something
              misconfigured, it will usually show up as an error with a
              message similar to 'Illegal mix of collations'.</p></li><li><p><span class="emphasis"><em>Server-side Prepared Statements</em></span> -
              Connector/J 3.1 will automatically detect and use server-side
              prepared statements when they are available (MySQL server
              version 4.1.0 and newer).</p><p>Starting with version 3.1.7, the driver scans SQL you are
              preparing via all variants of
              <tt class="methodname">Connection.prepareStatement()</tt> to
              determine if it is a supported type of statement to prepare on
              the server side, and if it is not supported by the server, it
              instead prepares it as a client-side emulated prepared
              statement. You can disable this feature by passing
              <span class="property">'emulateUnsupportedPstmts=false'</span> in your
              JDBC URL.</p><p>If your application encounters issues with server-side
              prepared statements, you can revert to the older client-side
              emulated prepared statement code that is still presently used
              for MySQL servers older than 4.1.0 with the following connection
              property:</p><p><tt class="computeroutput">useServerPrepStmts=false</tt></p></li><li><p>Datetimes with all-zero components ('0000-00-00 ...') -
              These values can not be represented reliably in Java.
              Connector/J 3.0.x always converted them to NULL when being read
              from a ResultSet.</p><p>Connector/J 3.1 throws an exception by default when these
              values are encountered as this is the most correct behavior
              according to the JDBC and SQL standards. This behavior can be
              modified using the '<span class="property">zeroDateTimeBehavior</span>'
              configuration property. The allowable values are: 'exception'
              (the default), which throws a SQLException with a SQLState of
              'S1009', 'convertToNull', which returns NULL instead of the
              date, and 'round', which rounds the date to the nearest closest
              value which is '0001-01-01'.</p><p>Starting with Connector/J 3.1.7, ResultSet.getString() can
              be decoupled from this behavior via
              '<span class="property">noDatetimeStringSync=true</span>' (the default
              value is 'false') so that you can get retrieve the unaltered
              all-zero value as a String. It should be noted that this also
              precludes using any timezone conversions, therefore the driver
              will not allow you to enable
              <span class="property">noDatetimeStringSync</span> and
              <span class="property">useTimezone</span> at the same time.</p></li><li><p>New SQLState Codes - Connector/J 3.1 uses SQL:1999
              SQLState codes returned by the MySQL server (if supported),
              which are different than the "legacy" X/Open state codes that
              Connector/J 3.0 uses. If connected to a MySQL server older than
              MySQL-4.1.0 (the oldest version to return SQLStates as part of
              the error code), the driver will use a built-in mapping. You can
              revert to the old mapping by using the following configuration
              property:</p><p><tt class="computeroutput">useSqlStateCodes=false</tt></p></li><li><p>Calling ResultSet.getString() on a BLOB column will now
              return the address of the byte[] array that represents it,
              instead of a String representation of the BLOB. BLOBs have no
              character set, so they can't be converted to java.lang.Strings
              without data loss or corruption.</p><p>To store strings in MySQL with LOB behavior, use one of
              the TEXT types, which the driver will treat as a
              java.sql.Clob.</p></li><li><p>Starting with Connector/J 3.1.8 a "debug" build of the
              driver in a file named
              "<tt class="filename">mysql-connector-java-[version]-bin-g.jar</tt>"
              is shipped alongside the normal "binary" jar file that is named
              "<tt class="filename">mysql-connector-java-[version]-bin.jar</tt>".</p><p>Starting with Connector/J 3.1.9, we don't ship the .class
              files "unbundled", they are only available in the JAR archives
              that ship with the driver.</p><p>You should not use the "debug" build of the driver unless
              instructed do do so when reporting a problem or bug to MySQL AB,
              as it is not designed to be run in production environments, and
              will have adverse performance impact when used. The debug binary
              also depends on the Aspect/J runtime library, which is located
              in the <tt class="filename">src/lib/aspectjrt.jar</tt> file that
              comes with the Connector/J distribution.</p></li></ul></div></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="cj-jdbc-upgrading-issues"></a>1.2.2.2.&nbsp;JDBC-Specific Issues When Upgrading to MySQL Server Version
          4.1 or Newer</h4></div></div><div></div></div><p><div class="itemizedlist"><ul type="disc"><li><p><span class="emphasis"><em>Using the UTF-8 Character Encoding</em></span>
                - Prior to MySQL server version 4.1, the UTF-8 character
                encoding was not supported by the server, however the JDBC
                driver could use it, allowing storage of multiple character
                sets in latin1 tables on the server.</p><p>Starting with MySQL-4.1, this functionality is
                deprecated. If you have applications that rely on this
                functionality, and can not upgrade them to use the official
                Unicode character support in MySQL server version 4.1 or
                newer, you should add the following property to your
                connection URL:</p><p><tt class="computeroutput">useOldUTF8Behavior=true</tt></p></li><li><p><span class="emphasis"><em>Server-side Prepared Statements</em></span> -
                Connector/J 3.1 will automatically detect and use server-side
                prepared statements when they are available (MySQL server
                version 4.1.0 and newer). If your application encounters
                issues with server-side prepared statements, you can revert to
                the older client-side emulated prepared statement code that is
                still presently used for MySQL servers older than 4.1.0 with
                the following connection property:</p><p><tt class="computeroutput">useServerPrepStmts=false</tt></p></li></ul></div></p></div></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="cj-jdbc-reference"></a>1.3.&nbsp;JDBC Reference</h2></div></div><div></div></div><p></p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="cj-configuration-properties"></a>1.3.1.&nbsp;Driver/Datasource Class Names, URL Syntax and Configuration
        Properties for Connector/J</h3></div></div><div></div></div><p>The name of the class that implements java.sql.Driver in MySQL
        Connector/J is 'com.mysql.jdbc.Driver'. The 'org.gjt.mm.mysql.Driver'
        class name is also usable to remain backwards-compatible with
        MM.MySQL. You should use this class name when registering the driver,
        or when otherwise configuring software to use MySQL
        Connector/J.</p><p>The JDBC URL format for MySQL Connector/J is as follows, with
        items in square brackets ([, ]) being optional:<pre class="screen">jdbc:mysql://[host][,failoverhost...][:port]/[database][?propertyName1][=propertyValue1][&amp;propertyName2][=propertyValue2]...</pre></p><p>If the hostname is not specified, it defaults to '127.0.0.1'. If
        the port is not specified, it defaults to '3306', the default port
        number for MySQL servers.</p><pre class="screen">jdbc:mysql://[host:port],[host:port].../[database][?propertyName1][=propertyValue1][&amp;propertyName2][=propertyValue2]...</pre><p>If the database is not specified, the connection will be made
        with no 'current' database. In this case, you will need to either call
        the 'setCatalog()' method on the Connection instance or fully-specify
        table names using the database name (i.e. 'SELECT
        dbname.tablename.colname FROM dbname.tablename...') in your SQL. Not
        specifying the database to use upon connection is generally only
        useful when building tools that work with multiple databases, such as
        GUI database managers.</p><p>MySQL Connector/J has fail-over support. This allows the driver
        to fail-over to any number of "slave" hosts and still perform
        read-only queries. Fail-over only happens when the connection is in an
        autoCommit(true) state, because fail-over can not happen reliably when
        a transaction is in progress. Most application servers and connection
        pools set autoCommit to 'true' at the end of every
        transaction/connection use.</p><p>The fail-over functionality has the following behavior:</p><p>If the URL property "autoReconnect" is false: Failover only
        happens at connection initialization, and failback occurs when the
        driver determines that the first host has become available
        again.</p><p>If the URL property "autoReconnect" is true: Failover happens
        when the driver determines that the connection has failed (before
        <span class="emphasis"><em>every</em></span> query), and falls back to the first host
        when it determines that the host has become available again (after
        queriesBeforeRetryMaster queries have been issued).</p><p>In either case, whenever you are connected to a "failed-over"
        server, the connection will be set to read-only state, so queries that
        would modify data will have exceptions thrown (the query will
        <span class="emphasis"><em>never</em></span> be processed by the MySQL server).</p><p>Configuration properties define how Connector/J will make a
        connection to a MySQL server. Unless otherwise noted, properties can
        be set for a DataSource object or for a Connection object.</p><p>Configuration Properties can be set in one of the following
        ways:<div class="itemizedlist"><ul type="disc"><li><p>Using the set*() methods on MySQL implementations of
              java.sql.DataSource:<div class="itemizedlist"><ul type="circle"><li><p>com.mysql.jdbc.jdbc2.optional.MysqlDataSource</p></li><li><p>com.mysql.jdbc.jdbc2.optional.MysqlConnectionPoolDataSource</p></li></ul></div></p></li><li><p>As a key/value pair in the java.util.Properties instance
              passed to DriverManager.getConnection() or
              Driver.connect()</p></li><li><p>As a JDBC URL parameter in the URL given to
              java.sql.DriverManager.getConnection(),
              java.sql.Driver.connect() or the MySQL implementations of
              javax.sql.DataSource's setURL() method.<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>If the mechanism you use to configure a JDBC URL is
                  XML-based, you will need to use the XML character literal
                  &amp;amp; to separate configuration parameters, as the
                  ampersand is a reserved character for XML.</p></div></p></li></ul></div>The properties are listed in the following
        table:</p><div class="table"><a name="N1025C"></a><p class="title"><b>Table&nbsp;1.1.&nbsp;Connection Properties</b></p><table summary="Connection Properties" border="1"><colgroup><col><col><col><col><col></colgroup><thead><tr><th>Property Name</th><th>Definition</th><th>Required?</th><th>Default Value</th><th>Since Version</th></tr></thead><tbody><tr><td colspan="5"><span class="emphasis"><em>Connection/Authentication</em></span></td></tr><tr><td>user</td><td>The user to connect as</td><td>No</td><td>&nbsp;</td><td>all</td></tr><tr><td>password</td><td>The password to use when connecting</td><td>No</td><td>&nbsp;</td><td>all</td></tr><tr><td>socketFactory</td><td>The name of the class that the driver should use for
                creating socket connections to the server. This class must
                implement the interface 'com.mysql.jdbc.SocketFactory' and
                have public no-args constructor.</td><td>No</td><td>com.mysql.jdbc.StandardSocketFactory</td><td>3.0.3</td></tr><tr><td>connectTimeout</td><td>Timeout for socket connect (in milliseconds), with 0
                being no timeout. Only works on JDK-1.4 or newer. Defaults to
                '0'.</td><td>No</td><td>0</td><td>3.0.1</td></tr><tr><td>socketTimeout</td><td>Timeout on network socket operations (0, the default
                means no timeout).</td><td>No</td><td>0</td><td>3.0.1</td></tr><tr><td>useConfigs</td><td>Load the comma-delimited list of configuration
                properties before parsing the URL or applying user-specified
                properties. These configurations are explained in the
                'Configurations' of the documentation.</td><td>No</td><td>&nbsp;</td><td>3.1.5</td></tr><tr><td>interactiveClient</td><td>Set the CLIENT_INTERACTIVE flag, which tells MySQL to
                timeout connections based on INTERACTIVE_TIMEOUT instead of
                WAIT_TIMEOUT</td><td>No</td><td>false</td><td>3.1.0</td></tr><tr><td>propertiesTransform</td><td>An implementation of
                com.mysql.jdbc.ConnectionPropertiesTransform that the driver
                will use to modify URL properties passed to the driver before
                attempting a connection</td><td>No</td><td>&nbsp;</td><td>3.1.4</td></tr><tr><td>useCompression</td><td>Use zlib compression when communicating with the server
                (true/false)? Defaults to 'false'.</td><td>No</td><td>false</td><td>3.0.17</td></tr><tr><td colspan="5"><span class="emphasis"><em>High
                Availability and Clustering</em></span></td></tr><tr><td>autoReconnect</td><td>Should the driver try to re-establish bad
                connections?</td><td>No</td><td>false</td><td>1.1</td></tr><tr><td>autoReconnectForPools</td><td>Use a reconnection strategy appropriate for connection
                pools (defaults to 'false')</td><td>No</td><td>false</td><td>3.1.3</td></tr><tr><td>failOverReadOnly</td><td>When failing over in autoReconnect mode, should the
                connection be set to 'read-only'?</td><td>No</td><td>true</td><td>3.0.12</td></tr><tr><td>reconnectAtTxEnd</td><td>If autoReconnect is set to true, should the driver
                attempt reconnectionsat the end of every transaction?</td><td>No</td><td>false</td><td>3.0.10</td></tr><tr><td>roundRobinLoadBalance</td><td>When autoReconnect is enabled, and failoverReadonly is
                false, should we pick hosts to connect to on a round-robin
                basis?</td><td>No</td><td>false</td><td>3.1.2</td></tr><tr><td>queriesBeforeRetryMaster</td><td>Number of queries to issue before falling back to
                master when failed over (when using multi-host failover).
                Whichever condition is met first, 'queriesBeforeRetryMaster'
                or 'secondsBeforeRetryMaster' will cause an attempt to be made
                to reconnect to the master. Defaults to 50.</td><td>No</td><td>50</td><td>3.0.2</td></tr><tr><td>secondsBeforeRetryMaster</td><td>How long should the driver wait, when failed over,
                before attempting to reconnect to the master server? Whichever
                condition is met first, 'queriesBeforeRetryMaster' or
                'secondsBeforeRetryMaster' will cause an attempt to be made to
                reconnect to the master. Time in seconds, defaults to
                30</td><td>No</td><td>30</td><td>3.0.2</td></tr><tr><td>enableDeprecatedAutoreconnect</td><td>Auto-reconnect functionality is deprecated starting
                with version 3.2, and will be removed in version 3.3. Set this
                property to 'true' to disable the check for the feature being
                configured.</td><td>No</td><td>false</td><td>3.2.1</td></tr><tr><td colspan="5"><span class="emphasis"><em>Security</em></span></td></tr><tr><td>allowMultiQueries</td><td>Allow the use of ';' to delimit multiple queries during
                one statement (true/false, defaults to 'false'</td><td>No</td><td>false</td><td>3.1.1</td></tr><tr><td>useSSL</td><td>Use SSL when communicating with the server
                (true/false), defaults to 'false'</td><td>No</td><td>false</td><td>3.0.2</td></tr><tr><td>requireSSL</td><td>Require SSL connection if useSSL=true? (defaults to
                'false').</td><td>No</td><td>false</td><td>3.1.0</td></tr><tr><td>allowUrlInLocalInfile</td><td>Should the driver allow URLs in 'LOAD DATA LOCAL
                INFILE' statements?</td><td>No</td><td>false</td><td>3.1.4</td></tr><tr><td>paranoid</td><td>Take measures to prevent exposure sensitive information
                in error messages and clear data structures holding sensitive
                data when possible? (defaults to 'false')</td><td>No</td><td>false</td><td>3.0.1</td></tr><tr><td colspan="5"><span class="emphasis"><em>Performance
                Extensions</em></span></td></tr><tr><td>metadataCacheSize</td><td>The number of queries to cacheResultSetMetadata for if
                cacheResultSetMetaData is set to 'true' (default 50)</td><td>No</td><td>50</td><td>3.1.1</td></tr><tr><td>prepStmtCacheSize</td><td>If prepared statement caching is enabled, how many
                prepared statements should be cached?</td><td>No</td><td>25</td><td>3.0.10</td></tr><tr><td>prepStmtCacheSqlLimit</td><td>If prepared statement caching is enabled, what's the
                largest SQL the driver will cache the parsing for?</td><td>No</td><td>256</td><td>3.0.10</td></tr><tr><td>maintainTimeStats</td><td>Should the driver maintain various internal timers to
                enable idle time calculations as well as more verbose error
                messages when the connection to the server fails? Setting this
                property to false removes at least two calls to
                System.getCurrentTimeMillis() per query.</td><td>No</td><td>true</td><td>3.1.9</td></tr><tr><td>blobSendChunkSize</td><td>Chunk to use when sending BLOB/CLOBs via
                ServerPreparedStatements</td><td>No</td><td>1048576</td><td>3.1.9</td></tr><tr><td>cacheCallableStmts</td><td>Should the driver cache the parsing stage of
                CallableStatements</td><td>No</td><td>false</td><td>3.1.2</td></tr><tr><td>cachePrepStmts</td><td>Should the driver cache the parsing stage of
                PreparedStatements of client-side prepared statements, the
                "check" for suitability of server-side prepared and
                server-side prepared statements themselves?</td><td>No</td><td>false</td><td>3.0.10</td></tr><tr><td>cacheResultSetMetadata</td><td>Should the driver cache ResultSetMetaData for
                Statements and PreparedStatements? (Req. JDK-1.4+, true/false,
                default 'false')</td><td>No</td><td>false</td><td>3.1.1</td></tr><tr><td>cacheServerConfiguration</td><td>Should the driver cache the results of 'SHOW VARIABLES'
                and 'SHOW COLLATION' on a per-URL basis?</td><td>No</td><td>false</td><td>3.1.5</td></tr><tr><td>dontTrackOpenResources</td><td>The JDBC specification requires the driver to
                automatically track and close resources, however if your
                application doesn't do a good job of explicitly calling
                close() on statements or result sets, this can cause memory
                leakage. Setting this property to true relaxes this
                constraint, and can be more memory efficient for some
                applications.</td><td>No</td><td>false</td><td>3.1.7</td></tr><tr><td>dynamicCalendars</td><td>Should the driver retrieve the default calendar when
                required, or cache it per connection/session?</td><td>No</td><td>false</td><td>3.1.5</td></tr><tr><td>elideSetAutoCommits</td><td>If using MySQL-4.1 or newer, should the driver only
                issue 'set autocommit=n' queries when the server's state
                doesn't match the requested state by
                Connection.setAutoCommit(boolean)?</td><td>No</td><td>false</td><td>3.1.3</td></tr><tr><td>holdResultsOpenOverStatementClose</td><td>Should the driver close result sets on
                Statement.close() as required by the JDBC
                specification?</td><td>No</td><td>false</td><td>3.1.7</td></tr><tr><td>locatorFetchBufferSize</td><td>If 'emulateLocators' is configured to 'true', what size
                buffer should be used when fetching BLOB data for
                getBinaryInputStream?</td><td>No</td><td>1048576</td><td>3.2.1</td></tr><tr><td>useFastIntParsing</td><td>Use internal String-&gt;Integer conversion routines to
                avoid excessive object creation?</td><td>No</td><td>true</td><td>3.1.4</td></tr><tr><td>useLocalSessionState</td><td>Should the driver refer to the internal values of
                autocommit and transaction isolation that are set by
                Connection.setAutoCommit() and
                Connection.setTransactionIsolation(), rather than querying the
                database?</td><td>No</td><td>false</td><td>3.1.7</td></tr><tr><td>useNewIO</td><td>Should the driver use the java.nio.* interfaces for
                network communication (true/false), defaults to
                'false'</td><td>No</td><td>false</td><td>3.1.0</td></tr><tr><td>useReadAheadInput</td><td>Use newer, optimized non-blocking, buffered input
                stream when reading from the server?</td><td>No</td><td>true</td><td>3.1.5</td></tr><tr><td colspan="5"><span class="emphasis"><em>Debuging/Profiling</em></span></td></tr><tr><td>logger</td><td>The name of a class that implements
                'com.mysql.jdbc.log.Log' that will be used to log messages
                to.(default is 'com.mysql.jdbc.log.StandardLogger', which logs
                to STDERR)</td><td>No</td><td>com.mysql.jdbc.log.StandardLogger</td><td>3.1.1</td></tr><tr><td>profileSQL</td><td>Trace queries and their execution/fetch times to the
                configured logger (true/false) defaults to 'false'</td><td>No</td><td>false</td><td>3.1.0</td></tr><tr><td>reportMetricsIntervalMillis</td><td>If 'gatherPerfMetrics' is enabled, how often should
                they be logged (in ms)?</td><td>No</td><td>30000</td><td>3.1.2</td></tr><tr><td>maxQuerySizeToLog</td><td>Controls the maximum length/size of a query that will
                get logged when profiling or tracing</td><td>No</td><td>2048</td><td>3.1.3</td></tr><tr><td>packetDebugBufferSize</td><td>The maximum number of packets to retain when
                'enablePacketDebug' is true</td><td>No</td><td>20</td><td>3.1.3</td></tr><tr><td>slowQueryThresholdMillis</td><td>If 'logSlowQueries' is enabled, how long should a query
                (in ms) before it is logged as 'slow'?</td><td>No</td><td>2000</td><td>3.1.2</td></tr><tr><td>useUsageAdvisor</td><td>Should the driver issue 'usage' warnings advising
                proper and efficient usage of JDBC and MySQL Connector/J to
                the log (true/false, defaults to 'false')?</td><td>No</td><td>false</td><td>3.1.1</td></tr><tr><td>autoGenerateTestcaseScript</td><td>Should the driver dump the SQL it is executing,
                including server-side prepared statements to STDERR?</td><td>No</td><td>false</td><td>3.1.9</td></tr><tr><td>dumpQueriesOnException</td><td>Should the driver dump the contents of the query sent
                to the server in the message for SQLExceptions?</td><td>No</td><td>false</td><td>3.1.3</td></tr><tr><td>enablePacketDebug</td><td>When enabled, a ring-buffer of 'packetDebugBufferSize'
                packets will be kept, and dumped when exceptions are thrown in
                key areas in the driver's code</td><td>No</td><td>false</td><td>3.1.3</td></tr><tr><td>explainSlowQueries</td><td>If 'logSlowQueries' is enabled, should the driver
                automatically issue an 'EXPLAIN' on the server and send the
                results to the configured log at a WARN level?</td><td>No</td><td>false</td><td>3.1.2</td></tr><tr><td>logSlowQueries</td><td>Should queries that take longer than
                'slowQueryThresholdMillis' be logged?</td><td>No</td><td>false</td><td>3.1.2</td></tr><tr><td>traceProtocol</td><td>Should trace-level network protocol be logged?</td><td>No</td><td>false</td><td>3.1.2</td></tr><tr><td colspan="5"><span class="emphasis"><em>Miscellaneous</em></span></td></tr><tr><td>useUnicode</td><td>Should the driver use Unicode character encodings when
                handling strings? Should only be used when the driver can't
                determine the character set mapping, or you are trying to
                'force' the driver to use a character set that MySQL either
                doesn't natively support (such as UTF-8), true/false, defaults
                to 'true'</td><td>No</td><td>false</td><td>1.1g</td></tr><tr><td>characterEncoding</td><td>If 'useUnicode' is set to true, what character encoding
                should the driver use when dealing with strings? (defaults is
                to 'autodetect')</td><td>No</td><td>&nbsp;</td><td>1.1g</td></tr><tr><td>characterSetResults</td><td>Character set to tell the server to return results
                as.</td><td>No</td><td>&nbsp;</td><td>3.0.13</td></tr><tr><td>connectionCollation</td><td>If set, tells the server to use this collation via 'set
                connection_collation'</td><td>No</td><td>&nbsp;</td><td>3.0.13</td></tr><tr><td>sessionVariables</td><td>A comma-separated list of name/value pairs to be sent
                as SET SESSION ... to the server when the driver
                connects.</td><td>No</td><td>&nbsp;</td><td>3.1.8</td></tr><tr><td>allowNanAndInf</td><td>Should the driver allow NaN or +/- INF values in
                PreparedStatement.setDouble()?</td><td>No</td><td>false</td><td>3.1.5</td></tr><tr><td>autoDeserialize</td><td>Should the driver automatically detect and de-serialize
                objects stored in BLOB fields?</td><td>No</td><td>false</td><td>3.1.5</td></tr><tr><td>capitalizeTypeNames</td><td>Capitalize type names in DatabaseMetaData? (usually
                only useful when using WebObjects, true/false, defaults to
                'false')</td><td>No</td><td>false</td><td>2.0.7</td></tr><tr><td>clobberStreamingResults</td><td>This will cause a 'streaming' ResultSet to be
                automatically closed, and any outstanding data still streaming
                from the server to be discarded if another query is executed
                before all the data has been read from the server.</td><td>No</td><td>false</td><td>3.0.9</td></tr><tr><td>continueBatchOnError</td><td>Should the driver continue processing batch commands if
                one statement fails. The JDBC spec allows either way (defaults
                to 'true').</td><td>No</td><td>true</td><td>3.0.3</td></tr><tr><td>createDatabaseIfNotExist</td><td>Creates the database given in the URL if it doesn't yet
                exist. Assumes the configured user has permissions to create
                databases.</td><td>No</td><td>false</td><td>3.1.9</td></tr><tr><td>emptyStringsConvertToZero</td><td>Should the driver allow conversions from empty string
                fields to numeric values of '0'?</td><td>No</td><td>true</td><td>3.1.8</td></tr><tr><td>emulateLocators</td><td>N/A</td><td>No</td><td>false</td><td>3.1.0</td></tr><tr><td>emulateUnsupportedPstmts</td><td>Should the driver detect prepared statements that are
                not supported by the server, and replace them with client-side
                emulated versions?</td><td>No</td><td>true</td><td>3.1.7</td></tr><tr><td>ignoreNonTxTables</td><td>Ignore non-transactional table warning for rollback?
                (defaults to 'false').</td><td>No</td><td>false</td><td>3.0.9</td></tr><tr><td>jdbcCompliantTruncation</td><td>Should the driver throw java.sql.DataTruncation
                exceptions when data is truncated as is required by the JDBC
                specification when connected to a server that supports
                warnings(MySQL 4.1.0 and newer)?</td><td>No</td><td>true</td><td>3.1.2</td></tr><tr><td>maxRows</td><td>The maximum number of rows to return (0, the default
                means return all rows).</td><td>No</td><td>-1</td><td>all versions</td></tr><tr><td>noDatetimeStringSync</td><td>Don't ensure that
                ResultSet.getDatetimeType().toString().equals(ResultSet.getString())</td><td>No</td><td>false</td><td>3.1.7</td></tr><tr><td>nullCatalogMeansCurrent</td><td>When DatabaseMetadataMethods ask for a 'catalog'
                parameter, does the value null mean use the current catalog?
                (this is not JDBC-compliant, but follows legacy behavior from
                earlier versions of the driver)</td><td>No</td><td>true</td><td>3.1.8</td></tr><tr><td>nullNamePatternMatchesAll</td><td>Should DatabaseMetaData methods that accept *pattern
                parameters treat null the same as '%' (this is not
                JDBC-compliant, however older versions of the driver accepted
                this departure from the specification)</td><td>No</td><td>true</td><td>3.1.8</td></tr><tr><td>pedantic</td><td>Follow the JDBC spec to the letter.</td><td>No</td><td>false</td><td>3.0.0</td></tr><tr><td>relaxAutoCommit</td><td>If the version of MySQL the driver connects to does not
                support transactions, still allow calls to commit(),
                rollback() and setAutoCommit() (true/false, defaults to
                'false')?</td><td>No</td><td>false</td><td>2.0.13</td></tr><tr><td>rollbackOnPooledClose</td><td>Should the driver issue a rollback() when the logical
                connection in a pool is closed?</td><td>No</td><td>true</td><td>3.0.15</td></tr><tr><td>runningCTS13</td><td>Enables workarounds for bugs in Sun's JDBC compliance
                testsuite version 1.3</td><td>No</td><td>false</td><td>3.1.7</td></tr><tr><td>serverTimezone</td><td>Override detection/mapping of timezone. Used when
                timezone from server doesn't map to Java timezone</td><td>No</td><td>&nbsp;</td><td>3.0.2</td></tr><tr><td>strictFloatingPoint</td><td>Used only in older versions of compliance test</td><td>No</td><td>false</td><td>3.0.0</td></tr><tr><td>strictUpdates</td><td>Should the driver do strict checking (all primary keys
                selected) of updatable result sets (true, false, defaults to
                'true')?</td><td>No</td><td>true</td><td>3.0.4</td></tr><tr><td>tinyInt1isBit</td><td>Should the driver treat the datatype TINYINT(1) as the
                BIT type (because the server silently converts BIT -&gt;
                TINYINT(1) when creating tables)?</td><td>No</td><td>true</td><td>3.0.16</td></tr><tr><td>transformedBitIsBoolean</td><td>If the driver converts TINYINT(1) to a different type,
                should it use BOOLEAN instead of BIT for future compatibility
                with MySQL-5.0, as MySQL-5.0 has a BIT type?</td><td>No</td><td>false</td><td>3.1.9</td></tr><tr><td>ultraDevHack</td><td>Create PreparedStatements for prepareCall() when
                required, because UltraDev is broken and issues a
                prepareCall() for _all_ statements? (true/false, defaults to
                'false')</td><td>No</td><td>false</td><td>2.0.3</td></tr><tr><td>useHostsInPrivileges</td><td>Add '@hostname' to users in
                DatabaseMetaData.getColumn/TablePrivileges() (true/false),
                defaults to 'true'.</td><td>No</td><td>true</td><td>3.0.2</td></tr><tr><td>useOldUTF8Behavior</td><td>Use the UTF-8 behavior the driver did when
                communicating with 4.0 and older servers</td><td>No</td><td>false</td><td>3.1.6</td></tr><tr><td>useOnlyServerErrorMessages</td><td>Don't prepend 'standard' SQLState error messages to
                error messages returned by the server.</td><td>No</td><td>true</td><td>3.0.15</td></tr><tr><td>useServerPrepStmts</td><td>Use server-side prepared statements if the server
                supports them? (defaults to 'true').</td><td>No</td><td>true</td><td>3.1.0</td></tr><tr><td>useSqlStateCodes</td><td>Use SQL Standard state codes instead of 'legacy'
                X/Open/SQL state codes (true/false), default is 'true'</td><td>No</td><td>true</td><td>3.1.3</td></tr><tr><td>useStreamLengthsInPrepStmts</td><td>Honor stream length parameter in
                PreparedStatement/ResultSet.setXXXStream() method calls
                (true/false, defaults to 'true')?</td><td>No</td><td>true</td><td>3.0.2</td></tr><tr><td>useTimezone</td><td>Convert time/date types between client and server
                timezones (true/false, defaults to 'false')?</td><td>No</td><td>false</td><td>3.0.2</td></tr><tr><td>useUnbufferedInput</td><td>Don't use BufferedInputStream for reading data from the
                server</td><td>No</td><td>true</td><td>3.0.11</td></tr><tr><td>yearIsDateType</td><td>Should the JDBC driver treat the MySQL type "YEAR" as a
                java.sql.Date, or as a SHORT?</td><td>No</td><td>true</td><td>3.1.9</td></tr><tr><td>zeroDateTimeBehavior</td><td>What should happen when the driver encounters DATETIME
                values that are composed entirely of zeroes (used by MySQL to
                represent invalid dates)? Valid values are 'exception',
                'round' and 'convertToNull'.</td><td>No</td><td>exception</td><td>3.1.4</td></tr></tbody></table></div><p>Connector/J also supports access to MySQL via named pipes on
        Windows NT/2000/XP using the 'NamedPipeSocketFactory' as a
        plugin-socket factory via the 'socketFactory' property. If you don't
        use a 'namedPipePath' property, the default of '\\.\pipe\MySQL' will
        be used. If you use the NamedPipeSocketFactory, the hostname and port
        number values in the JDBC url will be ignored.</p><p>Adding the following property to your URL will enable the
        NamedPipeSocketFactory:</p><p>socketFactory=com.mysql.jdbc.NamedPipeSocketFactory</p><p>Named pipes only work when connecting to a MySQL server on the
        same physical machine as the one the JDBC driver is being used on. In
        simple performance tests, it appears that named pipe access is between
        30%-50% faster than the standard TCP/IP access.</p><p>You can create your own socket factories by following the
        example code in
        <tt class="classname">com.mysql.jdbc.NamedPipeSocketFactory</tt>, or
        <tt class="classname">com.mysql.jdbc.StandardSocketFactory</tt>.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="cj-implementation-notes"></a>1.3.2.&nbsp;JDBC API Implementation Notes</h3></div></div><div></div></div><p>MySQL Connector/J passes all of the tests in the
        publicly-available version of Sun's JDBC compliance testsuite.
        However, in many places the JDBC specification is vague about how
        certain functionality should be implemented, or the specification
        allows leeway in implementation.</p><p>This section gives details on a interface-by-interface level
        about how certain implementation decisions may affect how you use
        MySQL Connector/J.</p><div class="itemizedlist"><ul type="disc"><li><p>Blob</p><p>The Blob implementation does not allow in-place modification
            (they are 'copies', as reported by the
            DatabaseMetaData.locatorsUpdateCopies() method). Because of this,
            you should use the corresponding PreparedStatement.setBlob() or
            ResultSet.updateBlob() (in the case of updatable result sets)
            methods to save changes back to the database.</p><p>Starting with Connector/J version 3.1.0, you can emulate
            Blobs with locators by adding the property 'emulateLocators=true'
            to your JDBC URL. You must then use a column alias with the value
            of the column set to the actual name of the Blob column in the
            SELECT that you write to retrieve the Blob. The SELECT must also
            reference only one table, the table must have a primary key, and
            the SELECT must cover all columns that make up the primary key.
            The driver will then delay loading the actual Blob data until you
            retrieve the Blob and call retrieval methods (getInputStream(),
            getBytes(), etc) on it.</p></li><li><p>CallableStatement</p><p>Starting with Connector/J 3.1.1, stored procedures are
            supported when connecting to MySQL version 5.0 or newer via the
            <tt class="classname">CallableStatement</tt> interface. Currently, the
            <tt class="function">getParameterMetaData()</tt> method of
            <tt class="classname">CallableStatement</tt> is not supported.</p></li><li><p>Clob</p><p>The Clob implementation does not allow in-place modification
            (they are 'copies', as reported by the
            DatabaseMetaData.locatorsUpdateCopies() method). Because of this,
            you should use the PreparedStatement.setClob() method to save
            changes back to the database. The JDBC API does not have a
            ResultSet.updateClob() method.</p></li><li><p>Connection</p><p>Unlike older versions of MM.MySQL the 'isClosed()' method
            does not "ping" the server to determine if it is alive. In
            accordance with the JDBC specification, it only returns true if
            'closed()' has been called on the connection. If you need to
            determine if the connection is still valid, you should issue a
            simple query, such as "SELECT 1". The driver will throw an
            exception if the connection is no longer valid.</p></li><li><p>DatabaseMetaData</p><p>Foreign Key information (getImported/ExportedKeys() and
            getCrossReference()) is only available from 'InnoDB'-type tables.
            However, the driver uses 'SHOW CREATE TABLE' to retrieve this
            information, so when other table types support foreign keys, the
            driver will transparently support them as well.</p></li><li><p>Driver</p></li><li><p>PreparedStatement</p><p>PreparedStatements are implemented by the driver, as MySQL
            does not have a prepared statement feature. Because of this, the
            driver does not implement getParameterMetaData() or getMetaData()
            as it would require the driver to have a complete SQL parser in
            the client.</p><p>Starting with version 3.1.0 MySQL Connector/J, server-side
            prepared statements and 'binary-encoded' result sets are used when
            the server supports them.</p><p>Take care when using a server-side prepared statement with
            "large" parameters that are set via setBinaryStream(),
            setAsciiStream(), setUnicodeStream(), setBlob(), or setClob(). If
            you want to re-execute the statement with any "large" parameter
            changed to a non-"large" parameter, it is necessary to call
            clearParameters() and set all parameters again. The reason for
            this is as follows:</p><div class="itemizedlist"><ul type="circle"><li><p>The driver streams the 'large' data 'out-of-band' to the
                prepared statement on the server side when the parameter is
                set (before execution of the prepared statement).</p></li></ul></div><div class="itemizedlist"><ul type="circle"><li><p>Once that has been done, the stream used to read the
                data on the client side is closed (as per the JDBC spec), and
                can't be read from again.</p></li></ul></div><div class="itemizedlist"><ul type="circle"><li><p>If a parameter changes from "large" to non-"large", the
                driver must reset the server-side state of the prepared
                statement to allow the parameter that is being changed to take
                the place of the prior "large" value. This removes all of the
                'large' data that has already been sent to the server, thus
                requiring the data to be re-sent, via the setBinaryStream(),
                setAsciiStream(), setUnicodeStream(), setBlob() or setClob()
                methods.</p></li></ul></div><p>Consequently, if you want to change the "type" of a
            parameter to a non-"large" one, you must call clearParameters()
            and set all parameters of the prepared statement again before it
            can be re-executed.</p></li><li><p>ResultSet</p><p>By default, ResultSets are completely retrieved and stored
            in memory. In most cases this is the most efficient way to
            operate, and due to the design of the MySQL network protocol is
            easier to implement. If you are working with ResultSets that have
            a large number of rows or large values, and can not allocate heap
            space in your JVM for the memory required, you can tell the driver
            to 'stream' the results back one row at-a-time.</p><p>To enable this functionality, you need to create a Statement
            instance in the following manner: <pre class="programlisting">
stmt = conn.createStatement(java.sql.ResultSet.TYPE_FORWARD_ONLY,
              java.sql.ResultSet.CONCUR_READ_ONLY);
stmt.setFetchSize(Integer.MIN_VALUE);</pre>The combination of a
            forward-only, read-only result set, with a fetch size of
            Integer.MIN_VALUE serves as a signal to the driver to "stream"
            result sets row-by-row. After this any result sets created with
            the statement will be retrieved row-by-row.</p><p>There are some caveats with this approach. You will have to
            read all of the rows in the result set (or close it) before you
            can issue any other queries on the connection, or an exception
            will be thrown.</p><p>The earliest the locks these statements hold can be released
            (whether they be MyISAM table-level locks or row-level locks in
            some other storage engine such as InnoDB) is when the statement
            completes.</p><p>If the statement is within scope of a transaction, then
            locks are released when the transaction completes (which implies
            that the statement needs to complete first). As with most other
            databases, statements are not complete until all the results
            pending on the statement are read or the active result set for the
            statement is closed.</p><p>Therefore, if using "streaming" results, you should process
            them as quickly as possible if you want to maintain concurrent
            access to the tables referenced by the statement producing the
            result set.</p></li><li><p>ResultSetMetaData</p><p>The "isAutoIncrement()" method only works when using MySQL
            servers 4.0 and newer.</p></li><li><p>Statement</p><p>When using versions of the JDBC driver earlier than 3.2.1,
            and connected to server versions earlier than 5.0.3, the
            "setFetchSize()" method has no effect, other than to toggle result
            set streaming as described above.</p><p>MySQL does not support SQL cursors, and the JDBC driver
            doesn't emulate them, so "setCursorName()" has no effect.</p></li></ul></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="cj-type-conversions"></a>1.3.3.&nbsp;Java, JDBC and MySQL Types</h3></div></div><div></div></div><p>MySQL Connector/J is flexible in the way it handles conversions
        between MySQL data types and Java data types.</p><p>In general, any MySQL data type can be converted to a
        java.lang.String, and any numerical type can be converted to any of
        the Java numerical types, although round-off, overflow, or loss of
        precision may occur.</p><p>Starting with Connector/J 3.1.0, the JDBC driver will issue
        warnings or throw DataTruncation exceptions as is required by the JDBC
        specification unless the connection was configured not to do so by
        using the property "jdbcCompliantTruncation" and setting it to
        "false".</p><p>The conversions that are always guaranteed to work are listed in
        the following table:</p><div class="table"><a name="N10713"></a><p class="title"><b>Table&nbsp;1.2.&nbsp;Conversion Table</b></p><table summary="Conversion Table" border="1"><colgroup><col><col></colgroup><thead><tr><th>These MySQL Data Types</th><th>Can always be converted to these Java types</th></tr></thead><tbody><tr><td><span class="type">CHAR, VARCHAR, BLOB, TEXT, ENUM, and
                SET</span></td><td><tt class="classname">java.lang.String, java.io.InputStream,
                java.io.Reader, java.sql.Blob,
                java.sql.Clob</tt></td></tr><tr><td><span class="type">FLOAT, REAL, DOUBLE PRECISION, NUMERIC, DECIMAL,
                TINYINT, SMALLINT, MEDIUMINT, INTEGER, BIGINT</span></td><td><tt class="classname">java.lang.String, java.lang.Short,
                java.lang.Integer, java.lang.Long, java.lang.Double,
                java.math.BigDecimal</tt><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>round-off, overflow or loss of precision may occur
                    if you choose a Java numeric data type that has less
                    precision or capacity than the MySQL data type you are
                    converting to/from.</p></div></td></tr><tr><td><span class="type">DATE, TIME, DATETIME, TIMESTAMP</span></td><td><tt class="classname">java.lang.String, java.sql.Date,
                java.sql.Timestamp</tt></td></tr></tbody></table></div><p>The <tt class="classname">ResultSet.getObject()</tt> method uses the
        following type conversions between MySQL and Java types, following the
        JDBC specification where appropriate:</p><p><div class="table"><a name="N1073D"></a><p class="title"><b>Table&nbsp;1.3.&nbsp;MySQL Types to Java Types for ResultSet.getObject()</b></p><table summary="MySQL Types to Java Types for ResultSet.getObject()" border="1"><colgroup><col><col></colgroup><thead><tr><th>MySQL Type Name</th><th>Returned as Java Class</th></tr></thead><tbody><tr><td><span class="type">BIT(1)</span> (new in MySQL-5.0)</td><td><tt class="classname">java.lang.Boolean</tt></td></tr><tr><td><span class="type">BIT( &gt; 1)</span> (new in MySQL-5.0)</td><td><tt class="classname">byte[]</tt></td></tr><tr><td><span class="type">TINYINT</span></td><td><tt class="classname">java.lang.Boolean</tt> if the
                  configuration property "tinyInt1isBit" is set to "true" (the
                  default) and the storage size is "1", or
                  <tt class="classname">java.lang.Integer</tt> if not.</td></tr><tr><td><span class="type">BOOL , BOOLEAN</span></td><td>See <span class="type">TINYINT</span>, above as these are aliases
                  for <span class="type">TINYINT(1)</span>, currently.</td></tr><tr><td><span class="type">SMALLINT[(M)] [UNSIGNED]</span></td><td><tt class="classname">java.lang.Integer</tt> (regardless
                  if UNSIGNED or not)</td></tr><tr><td><span class="type">MEDIUMINT[(M)] [UNSIGNED]</span></td><td><tt class="classname">java.lang.Integer</tt> (regardless
                  if UNSIGNED or not)</td></tr><tr><td><span class="type">INT,INTEGER[(M)] [UNSIGNED]</span></td><td><tt class="classname">java.lang.Integer</tt>, if UNSIGNED
                  <tt class="classname">java.lang.Long</tt></td></tr><tr><td><span class="type">BIGINT[(M)] [UNSIGNED]</span></td><td><tt class="classname">java.lang.Long</tt>, if UNSIGNED
                  <tt class="classname">java.math.BigInteger</tt></td></tr><tr><td><span class="type">FLOAT[(M,D)]</span></td><td><tt class="classname">java.lang.Float</tt></td></tr><tr><td><span class="type">DOUBLE[(M,B)]</span></td><td><tt class="classname">java.lang.Double</tt></td></tr><tr><td><span class="type">DECIMAL[(M[,D])]</span></td><td><tt class="classname">java.math.BigDecimal</tt></td></tr><tr><td><span class="type">DATE</span></td><td><tt class="classname">java.sql.Date</tt></td></tr><tr><td><span class="type">DATETIME</span></td><td><tt class="classname">java.sql.Timestamp</tt></td></tr><tr><td><span class="type">TIMESTAMP[(M)]</span></td><td><tt class="classname">java.sql.Timestamp</tt></td></tr><tr><td><span class="type">TIME</span></td><td><tt class="classname">java.sql.Time</tt></td></tr><tr><td><span class="type">YEAR[(2|4)]</span></td><td><tt class="classname">java.sql.Date</tt> (with the date
                  set two January 1st, at midnight)</td></tr><tr><td><span class="type">CHAR(M)</span></td><td><tt class="classname">java.lang.String</tt> (unless the
                  character set for the column is <span class="type">BINARY</span>, then
                  <tt class="classname">byte[]</tt> is returned.</td></tr><tr><td><span class="type">VARCHAR(M) [BINARY]</span></td><td><tt class="classname">java.lang.String</tt> (unless the
                  character set for the column is <span class="type">BINARY</span>, then
                  <tt class="classname">byte[]</tt> is returned.</td></tr><tr><td><span class="type">BINARY(M)</span></td><td><tt class="classname">byte[]</tt></td></tr><tr><td><span class="type">VARBINARY(M)</span></td><td><tt class="classname">byte[]</tt></td></tr><tr><td><span class="type">TINYBLOB</span></td><td><tt class="classname">byte[]</tt></td></tr><tr><td><span class="type">TINYTEXT</span></td><td><tt class="classname">java.lang.String</tt></td></tr><tr><td><span class="type">BLOB</span></td><td><tt class="classname">byte[]</tt></td></tr><tr><td><span class="type">TEXT</span></td><td><tt class="classname">java.lang.String</tt></td></tr><tr><td><span class="type">MEDIUMBLOB</span></td><td><tt class="classname">byte[]</tt></td></tr><tr><td><span class="type">MEDIUMTEXT</span></td><td><tt class="classname">java.lang.String</tt></td></tr><tr><td><span class="type">LONGBLOB</span></td><td><tt class="classname">byte[]</tt></td></tr><tr><td><span class="type">LONGTEXT</span></td><td><tt class="classname">java.lang.String</tt></td></tr><tr><td><span class="type">ENUM('value1','value2',...)</span></td><td><tt class="classname">java.lang.String</tt></td></tr><tr><td><span class="type">SET('value1','value2',...)</span></td><td><tt class="classname">java.lang.String</tt></td></tr></tbody></table></div></p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="cj-character-sets"></a>1.3.4.&nbsp;Using Character Sets and Unicode</h3></div></div><div></div></div><p>All strings sent from the JDBC driver to the server are
        converted automatically from native Java Unicode form to the client
        character encoding, including all queries sent via
        <tt class="methodname">Statement.execute()</tt>,
        <tt class="methodname">Statement.executeUpdate()</tt>,
        <tt class="methodname">Statement.executeQuery()</tt> as well as all
        <tt class="interfacename">PreparedStatement</tt> and
        <tt class="interfacename">CallableStatement</tt> parameters with the
        exclusion of parameters set using <tt class="methodname">setBytes()</tt>,
        <tt class="methodname">setBinaryStream()</tt>,
        <tt class="methodname">setAsiiStream()</tt>,
        <tt class="methodname">setUnicodeStream()</tt> and
        <tt class="methodname">setBlob()</tt>.</p><p>Prior to MySQL Server 4.1, Connector/J supported a single
        character encoding per connection, which could either be automatically
        detected from the server configuration, or could be configured by the
        user through the <i class="parameter"><tt>useUnicode</tt></i> and
        <i class="parameter"><tt>characterEncoding</tt></i> properties.</p><p>Starting with MySQL Server 4.1, Connector/J supports a single
        character encoding between client and server, and any number of
        character encodings for data returned by the server to the client in
        <tt class="classname">ResultSets</tt>.</p><p>The character encoding between client and server is
        automatically detected upon connection. The encoding used by the
        driver is specified on the server via the configuration variable
        '<i class="parameter"><tt>character_set</tt></i>' for server versions older than
        4.1.0 and '<i class="parameter"><tt>character_set_server</tt></i>' for server
        versions 4.1.0 and newer. See the "<a href="http://www.mysql.com/doc/en/Charset-server.html" target="_top">Server Character
        Set and Collation</a>" section in the MySQL server manual for more
        information.</p><p>To override the automatically-detected encoding on the client
        side, use the <i class="parameter"><tt>characterEncoding</tt></i> property in the
        URL used to connect to the server.</p><p>When specifying character encodings on the client side,
        Java-style names should be used. The following table lists Java-style
        names for MySQL character sets: <div class="table"><a name="N10886"></a><p class="title"><b>Table&nbsp;1.4.&nbsp;MySQL to Java Encoding Name Translations</b></p><table summary="MySQL to Java Encoding Name Translations" border="1"><colgroup><col><col></colgroup><thead><tr><th>MySQL Character Set Name</th><th>Java-Style Character Encoding Name</th></tr></thead><tbody><tr><td>usa7</td><td>US-ASCII</td></tr><tr><td>big5</td><td>Big5</td></tr><tr><td>gbk</td><td>GBK</td></tr><tr><td>sjis</td><td>SJIS</td></tr><tr><td>gb2312</td><td>EUC_CN</td></tr><tr><td>ujis</td><td>EUC_JP</td></tr><tr><td>euc_kr</td><td>EUC_KR</td></tr><tr><td>latin1</td><td>ISO8859_1</td></tr><tr><td>latin1_de</td><td>ISO8859_1</td></tr><tr><td>german1</td><td>ISO8859_1</td></tr><tr><td>danish</td><td>ISO8859_1</td></tr><tr><td>latin2</td><td>ISO8859_2</td></tr><tr><td>czech</td><td>ISO8859_2</td></tr><tr><td>hungarian</td><td>ISO8859_2</td></tr><tr><td>croat</td><td>ISO8859_2</td></tr><tr><td>greek</td><td>ISO8859_7</td></tr><tr><td>hebrew</td><td>ISO8859_8</td></tr><tr><td>latin5</td><td>ISO8859_9</td></tr><tr><td>latvian</td><td>ISO8859_13</td></tr><tr><td>latvian1</td><td>ISO8859_13</td></tr><tr><td>estonia</td><td>ISO8859_13</td></tr><tr><td>dos</td><td>Cp437</td></tr><tr><td>pclatin2</td><td>Cp852</td></tr><tr><td>cp866</td><td>Cp866</td></tr><tr><td>koi8_ru</td><td>KOI8_R</td></tr><tr><td>tis620</td><td>TIS620</td></tr><tr><td>win1250</td><td>Cp1250</td></tr><tr><td>win1250ch</td><td>Cp1250</td></tr><tr><td>win1251</td><td>Cp1251</td></tr><tr><td>cp1251</td><td>Cp1251</td></tr><tr><td>win1251ukr</td><td>Cp1251</td></tr><tr><td>cp1257</td><td>Cp1257</td></tr><tr><td>macroman</td><td>MacRoman</td></tr><tr><td>macce</td><td>MacCentralEurope</td></tr><tr><td>utf8</td><td>UTF-8</td></tr><tr><td>ucs2</td><td>UnicodeBig</td></tr></tbody></table></div></p><div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Warning</h3><p>Do not issue the query 'set names' with Connector/J, as the
          driver will not detect that the character set has changed, and will
          continue to use the character set detected during the initial
          connection setup.</p></div><p>To allow multiple character sets to be sent from the client, the
        "UTF-8" encoding should be used, either by configuring "utf8" as the
        default server character set, or by configuring the JDBC driver to use
        "UTF-8" through the <i class="parameter"><tt>characterEncoding</tt></i>
        property.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="cj-using-ssl"></a>1.3.5.&nbsp;Connecting Securely Using SSL</h3></div></div><div></div></div><p>SSL in MySQL Connector/J encrypts all data (other than the
        initial handshake) between the JDBC driver and the server. The
        performance penalty for enabling SSL is an increase in query
        processing time between 35% and 50%, depending on the size of the
        query, and the amount of data it returns.</p><p>For SSL Support to work, you must have the following:</p><div class="itemizedlist"><ul type="disc"><li><p>A JDK that includes JSSE (Java Secure Sockets Extension),
            like JDK-1.4.1 or newer. SSL does not currently work with a JDK
            that you can add JSSE to, like JDK-1.2.x or JDK-1.3.x due to the
            following JSSE bug: <a href="http://developer.java.sun.com/developer/bugParade/bugs/4273544.html" target="_top">http://developer.java.sun.com/developer/bugParade/bugs/4273544.html</a></p></li><li><p>A MySQL server that supports SSL and has been compiled and
            configured to do so, which is MySQL-4.0.4 or later, see: <a href="http://www.mysql.com/doc/en/Secure_connections.html" target="_top">http://www.mysql.com/doc/en/Secure_connections.html</a></p></li><li><p>A client certificate (covered later in this section)</p></li></ul></div><p>You will first need to import the MySQL server CA Certificate
        into a Java truststore. A sample MySQL server CA Certificate is
        located in the 'SSL' subdirectory of the MySQL source distribution.
        This is what SSL will use to determine if you are communicating with a
        secure MySQL server.</p><p>To use Java's 'keytool' to create a truststore in the current
        directory , and import the server's CA certificate ('cacert.pem'), you
        can do the following (assuming that'keytool' is in your path. It's
        located in the 'bin' subdirectory of your JDK or JRE):</p><p><pre class="programlisting">shell&gt; keytool -import -alias mysqlServerCACert -file cacert.pem -keystore truststore
        </pre></p><p>Keytool will respond with the following information:</p><p><pre class="programlisting">Enter keystore password:  *********
Owner: EMAILADDRESS=walrus@example.com, CN=Walrus, O=MySQL AB, L=Orenburg, ST=Some
-State, C=RU
Issuer: EMAILADDRESS=walrus@example.com, CN=Walrus, O=MySQL AB, L=Orenburg, ST=Som
e-State, C=RU
Serial number: 0
Valid from: Fri Aug 02 16:55:53 CDT 2002 until: Sat Aug 02 16:55:53 CDT 2003
Certificate fingerprints:
         MD5:  61:91:A0:F2:03:07:61:7A:81:38:66:DA:19:C4:8D:AB
         SHA1: 25:77:41:05:D5:AD:99:8C:14:8C:CA:68:9C:2F:B8:89:C3:34:4D:6C
Trust this certificate? [no]:  yes
Certificate was added to keystore</pre></p><p>You will then need to generate a client certificate, so that the
        MySQL server knows that it is talking to a secure client:</p><p><pre class="programlisting"> shell&gt; keytool -genkey -keyalg rsa -alias mysqlClientCertificate -keystore keystore </pre></p><p>Keytool will prompt you for the following information, and
        create a keystore named 'keystore' in the current directory.</p><p>You should respond with information that is appropriate for your
        situation:<pre class="programlisting">Enter keystore password:  *********
What is your first and last name?
  [Unknown]:  Matthews
What is the name of your organizational unit?
  [Unknown]:  Software Development
What is the name of your organization?
  [Unknown]:  MySQL AB
What is the name of your City or Locality?
  [Unknown]:  Flossmoor
What is the name of your State or Province?
  [Unknown]:  IL
What is the two-letter country code for this unit?
  [Unknown]:  US
Is &lt;CN=Matthews, OU=Software Development, O=MySQL AB,
 L=Flossmoor, ST=IL, C=US&gt; correct?
  [no]:  y

Enter key password for &lt;mysqlClientCertificate&gt;
        (RETURN if same as keystore password):</pre></p><p>Finally, to get JSSE to use the keystore and truststore that you
        have generated, you need to set the following system properties when
        you start your JVM, replacing 'path_to_keystore_file' with the full
        path to the keystore file you created, 'path_to_truststore_file' with
        the path to the truststore file you created, and using the appropriate
        password values for each property.</p><p><pre class="programlisting">-Djavax.net.ssl.keyStore=path_to_keystore_file
-Djavax.net.ssl.keyStorePassword=*********
-Djavax.net.ssl.trustStore=path_to_truststore_file
-Djavax.net.ssl.trustStorePassword=********* </pre></p><p>You will also need to set 'useSSL' to 'true' in your connection
        parameters for MySQL Connector/J, either by adding 'useSSL=true' to
        your URL, or by setting the property 'useSSL' to 'true' in the
        java.util.Properties instance you pass to
        DriverManager.getConnection().</p><p>You can test that SSL is working by turning on JSSE debugging
        (as detailed below), and look for the following key events:</p><p><pre class="programlisting">...
 *** ClientHello, v3.1
 RandomCookie:  GMT: 1018531834 bytes = { 199, 148, 180, 215, 74, 12, 54, 244, 0, 168, 55, 103, 215, 64, 16, 138, 225, 190, 132, 153, 2, 217, 219, 239, 202, 19, 121, 78 }
 Session ID:  {}
 Cipher Suites:  { 0, 5, 0, 4, 0, 9, 0, 10, 0, 18, 0, 19, 0, 3, 0, 17 }
 Compression Methods:  { 0 }
 ***
 [write] MD5 and SHA1 hashes:  len = 59
 0000: 01 00 00 37 03 01 3D B6   90 FA C7 94 B4 D7 4A 0C  ...7..=.......J.
 0010: 36 F4 00 A8 37 67 D7 40   10 8A E1 BE 84 99 02 D9  6...7g.@........
 0020: DB EF CA 13 79 4E 00 00   10 00 05 00 04 00 09 00  ....yN..........
 0030: 0A 00 12 00 13 00 03 00   11 01 00                 ...........
 main, WRITE:  SSL v3.1 Handshake, length = 59
 main, READ:  SSL v3.1 Handshake, length = 74
 *** ServerHello, v3.1
 RandomCookie:  GMT: 1018577560 bytes = { 116, 50, 4, 103, 25, 100, 58, 202, 79, 185, 178, 100, 215, 66, 254, 21, 83, 187, 190, 42, 170, 3, 132, 110, 82, 148, 160, 92 }
 Session ID:  {163, 227, 84, 53, 81, 127, 252, 254, 178, 179, 68, 63, 182, 158, 30, 11, 150, 79, 170, 76, 255, 92, 15, 226, 24, 17, 177, 219, 158, 177, 187, 143}
 Cipher Suite:  { 0, 5 }
 Compression Method: 0
 ***
 %% Created:  [Session-1, SSL_RSA_WITH_RC4_128_SHA]
 ** SSL_RSA_WITH_RC4_128_SHA
 [read] MD5 and SHA1 hashes:  len = 74
 0000: 02 00 00 46 03 01 3D B6   43 98 74 32 04 67 19 64  ...F..=.C.t2.g.d
 0010: 3A CA 4F B9 B2 64 D7 42   FE 15 53 BB BE 2A AA 03  :.O..d.B..S..*..
 0020: 84 6E 52 94 A0 5C 20 A3   E3 54 35 51 7F FC FE B2  .nR..\ ..T5Q....
 0030: B3 44 3F B6 9E 1E 0B 96   4F AA 4C FF 5C 0F E2 18  .D?.....O.L.\...
 0040: 11 B1 DB 9E B1 BB 8F 00   05 00                    ..........
 main, READ:  SSL v3.1 Handshake, length = 1712
 ...</pre></p><p>JSSE provides debugging (to STDOUT) when you set the following
        system property: -Djavax.net.debug=all This will tell you what
        keystores and truststores are being used, as well as what is going on
        during the SSL handshake and certificate exchange. It will be helpful
        when trying to determine what is not working when trying to get an SSL
        connection to happen.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="cj-replication-connection"></a>1.3.6.&nbsp;Using Master/Slave Replication with
        ReplicationConnection</h3></div></div><div></div></div><p>Starting with Connector/J 3.1.7, we've made available a variant
        of the driver that will automatically send queries to a read/write
        master, or a failover or round-robin loadbalanced set of slaves based
        on the state of <tt class="function">Connection.getReadOnly()</tt>.</p><p>An application signals that it wants a transaction to be
        read-only by calling
        <tt class="function">Connection.setReadOnly(true)</tt>, this
        "replication-aware" connection will use one of the slave connections,
        which are load-balanced per-vm using a round-robin scheme (a given
        connection is "sticky" to a slave unless that slave is removed from
        service). If you have a write transaction, or if you have a read that
        is "time-sensitive" (remember, replication in MySQL is asynchronous),
        set the connection to be not read-only, by calling
        <tt class="function">Connection.setReadOnly(false)</tt> and the driver will
        ensure that further calls are sent to the "master" MySQL server. The
        driver takes care of propagating the current state of autocommit,
        isolation level, and catalog between all of the connections that it
        uses to accomplish this load balancing functionality.</p><p>To enable this functionality, use the
        "<tt class="function">com.mysql.jdbc.ReplicationDriver</tt>" class when
        configuring your application server's connection pool or when creating
        an instance of a JDBC driver for your standalone application. Because
        it accepts the same URL format as the standard MySQL JDBC driver,
        <tt class="function">ReplicationDriver</tt> does not currently work with
        <tt class="function">java.sql.DriverManager</tt>-based connection creation
        unless it is the only MySQL JDBC driver registered with the
        <tt class="function">DriverManager</tt>.</p><p>Here is a short, simple example of how ReplicationDriver might
        be used in a standalone application.</p><a name="cj-using-replication-driver-example"></a><pre class="programlisting">import java.sql.Connection;
import java.sql.ResultSet;
import java.util.Properties;

import com.mysql.jdbc.ReplicationDriver;

public class ReplicationDriverDemo {

    public static void main(String[] args) throws Exception {
        ReplicationDriver driver = new ReplicationDriver();

        Properties props = new Properties();

        // We want this for failover on the slaves
        props.put("autoReconnect", "true");

        // We want to load balance between the slaves
        props.put("roundRobinLoadBalance", "true");

        props.put("user", "foo");
        props.put("password", "bar");

        //
        // Looks like a normal MySQL JDBC url, with a comma-separated list
        // of hosts, the first being the 'master', the rest being any number
        // of slaves that the driver will load balance against
        //

        Connection conn =
            driver.connect("jdbc:mysql://master,slave1,slave2,slave3/test",
                props);

        //
        // Perform read/write work on the master
        // by setting the read-only flag to "false"
        //

        conn.setReadOnly(false);
        conn.setAutoCommit(false);
        conn.createStatement().executeUpdate("UPDATE some_table ....");
        conn.commit();

        //
        // Now, do a query from a slave, the driver automatically picks one
        // from the list
        //

        conn.setReadOnly(true);

        ResultSet rs = conn.createStatement().executeQuery("SELECT a,b,c FROM some_other_table");

         .......
    }
}
</pre></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="cj-j2ee"></a>1.4.&nbsp;Using Connector/J with J2EE and Other Java Frameworks</h2></div></div><div></div></div><p></p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="cj-general-j2ee-concepts"></a>1.4.1.&nbsp;General J2EE Concepts</h3></div></div><div></div></div><p></p><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="cj-connection-pooling"></a>1.4.1.1.&nbsp;Understanding Connection Pooling</h4></div></div><div></div></div><p>Connection pooling is a technique of creating and managing a
          pool of connections that are ready for use by any thread that needs
          them.</p><p>This technique of "pooling" connections is based on the fact
          that most applications only need a thread to have access to a JDBC
          connection when they are actively processing a transaction, which
          usually take only milliseconds to complete. When not processing a
          transaction, the connection would otherwise sit idle. Instead,
          connection pooling allows the idle connection to be used by some
          other thread to do useful work.</p><p>In practice, when a thread needs to do work against a MySQL or
          other database with JDBC, it requests a connection from the pool.
          When the thread is finished using the connection, it returns it to
          the pool, so that it may be used by any other threads that want to
          use it.</p><p>When the connection is "loaned out" from the pool, it is used
          exclusively by the thread that requested it. From a programming
          point of view, it is the same as if your thread called
          DriverManager.getConnection() every time it needed a JDBC
          connection, however with connection pooling, your thread may end up
          using either a new, or already-existing connection.</p><p>Connection pooling can greatly increase the performance of
          your Java application, while reducing overall resource usage. The
          main benefits to connection pooling are:</p><div class="itemizedlist"><ul type="disc"><li><p>Reduced connection creation time</p><p>While this is not usually an issue with the quick
              connection setup that MySQL offers compared to other databases,
              creating new JDBC connections still incurs networking and JDBC
              driver overhead that will be avoided if connections are
              "recycled."</p></li><li><p>Simplified programming model</p><p>When using connection pooling, each individual thread can
              act as though it has created its own JDBC connection, allowing
              you to use straight-forward JDBC programming techniques.</p></li><li><p>Controlled resource usage</p><p>If you don't use connection pooling, and instead create a
              new connection every time a thread needs one, your application's
              resource usage can be quite wasteful and lead to unpredictable
              behavior under load.</p></li></ul></div><p>Remember that each connection to MySQL has overhead (memory,
          CPU, context switches, etc) on both the client and server side.
          Every connection limits how many resources there are available to
          your application as well as the MySQL server. Many of these
          resources will be used whether or not the connection is actually
          doing any useful work!</p><p>Connection pools can be tuned to maximize performance, while
          keeping resource utilization below the point where your application
          will start to fail rather than just run slower.</p><p>Luckily, Sun has standardized the concept of connection
          pooling in JDBC through the JDBC-2.0 "Optional" interfaces, and all
          major application servers have implementations of these APIs that
          work fine with MySQL Connector/J.</p><p>Generally, you configure a connection pool in your application
          server configuration files, and access it via the Java Naming and
          Directory Interface (JNDI). The following code shows how you might
          use a connection pool from an application deployed in a J2EE
          application server:<div class="example"><a name="N109EF"></a><p class="title"><b>Example&nbsp;1.12.&nbsp;Using a Connection Pool with a J2EE Application
              Server</b></p><pre class="programlisting">import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;

import javax.naming.InitialContext;
import javax.sql.DataSource;


public class MyServletJspOrEjb {

    public void doSomething() throws Exception {
        /*
         * Create a JNDI Initial context to be able to
         *  lookup  the DataSource
         *
         * In production-level code, this should be cached as
         * an instance or static variable, as it can
         * be quite expensive to create a JNDI context.
         *
         * Note: This code only works when you are using servlets
         * or EJBs in a J2EE application server. If you are
         * using connection pooling in standalone Java code, you
         * will have to create/configure datasources using whatever
         * mechanisms your particular connection pooling library
         * provides.
         */

        InitialContext ctx = new InitialContext();

         /*
          * Lookup the DataSource, which will be backed by a pool
          * that the application server provides. DataSource instances
          * are also a good candidate for caching as an instance
          * variable, as JNDI lookups can be expensive as well.
          */

        DataSource ds = (DataSource)ctx.lookup("java:comp/env/jdbc/MySQLDB");

        /*
         * The following code is what would actually be in your
         * Servlet, JSP or EJB 'service' method...where you need
         * to work with a JDBC connection.
         */

        Connection conn = null;
        Statement stmt = null;

        try {
            conn = ds.getConnection();

            /*
             * Now, use normal JDBC programming to work with
             * MySQL, making sure to close each resource when you're
             * finished with it, which allows the connection pool
             * resources to be recovered as quickly as possible
             */

            stmt = conn.createStatement();
            stmt.execute("SOME SQL QUERY");

            stmt.close();
            stmt = null;

            conn.close();
            conn = null;
        } finally {
            /*
             * close any jdbc instances here that weren't
             * explicitly closed during normal code path, so
             * that we don't 'leak' resources...
             */

            if (stmt != null) {
                try {
                    stmt.close();
                } catch (sqlexception sqlex) {
                    // ignore -- as we can't do anything about it here
                }

                stmt = null;
            }

            if (conn != null) {
                try {
                    conn.close();
                } catch (sqlexception sqlex) {
                    // ignore -- as we can't do anything about it here
                }

                conn = null;
            }
        }
    }
}</pre></div>As shown in the example above, after obtaining the JNDI
          InitialContext, and looking up the DataSource, the rest of the code
          should look familiar to anyone who has done JDBC programming in the
          past.</p><p>The most important thing to remember when using connection
          pooling is to make sure that no matter what happens in your code
          (exceptions, flow-of-control, etc), connections, and anything
          created by them (statements, result sets, etc) are closed, so that
          they may be re-used, otherwise they will be "stranded," which in the
          best case means that the MySQL server resources they represent
          (buffers, locks, sockets, etc) may be tied up for some time, or
          worst case, may be tied up forever.</p><p>What's the Best Size for my Connection Pool?</p><p>As with all other configuration rules-of-thumb, the answer is
          "It depends." While the optimal size depends on anticipated load and
          average database transaction time, the optimum connection pool size
          is smaller than you might expect. If you take Sun's Java Petstore
          blueprint application for example, a connection pool of 15-20
          connections can serve a relatively moderate load (600 concurrent
          users) using MySQL and Tomcat with response times that are
          acceptable.</p><p>To correctly size a connection pool for your application, you
          should create load test scripts with tools such as Apache JMeter or
          The Grinder, and load test your application.</p><p>An easy way to determine a starting point is to configure your
          connection pool's maximum number of connections to be "unbounded,"
          run a load test, and measure the largest amount of concurrently used
          connections. You can then work backwards from there to determine
          what values of minimum and maximum pooled connections give the best
          performance for your particular application.</p></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="cj-tomcat-config"></a>1.4.2.&nbsp;Using Connector/J with Tomcat</h3></div></div><div></div></div><p></p><p>The following instructions are based on the instructions for
        Tomcat-5.x, available at <a href="The following instructions are based on the instructions for Tomcat-5.x, available at http://jakarta.apache.org/tomcat/tomcat-5.0-doc/jndi-datasource-examples-howto.html which is current at the time this document was written." target="_top">http://jakarta.apache.org/tomcat/tomcat-5.0-doc/jndi-datasource-examples-howto.html</a>
        which is current at the time this document was written.</p><p>First, install the .jar file that comes with Connector/J in
        <tt class="filename">$CATALINA_HOME/common/lib</tt> so that it is available
        to all applications installed in the container.</p><p>Next, Configure the JNDI DataSource by adding a declaration
        resource to <tt class="filename">$CATALINA_HOME/conf/server.xml</tt> in the
        context that defines your web application:</p><pre class="programlisting">&lt;Context ....&gt;

  ...

  &lt;Resource name="jdbc/MySQLDB"
               auth="Container"
               type="javax.sql.DataSource"/&gt;

  &lt;!-- The name you used above, must match _exactly_ here!

       The connection pool will be bound into JNDI with the name
       "java:/comp/env/jdbc/MySQLDB"
  --&gt;

  &lt;ResourceParams name="jdbc/MySQLDB"&gt;
    &lt;parameter&gt;
      &lt;name&gt;factory&lt;/name&gt;
      &lt;value&gt;org.apache.commons.dbcp.BasicDataSourceFactory&lt;/value&gt;
    &lt;/parameter&gt;

    &lt;!-- Don't set this any higher than max_connections on your
         MySQL server, usually this should be a 10 or a few 10's
         of connections, not hundreds or thousands --&gt;

    &lt;parameter&gt;
      &lt;name&gt;maxActive&lt;/name&gt;
      &lt;value&gt;10&lt;/value&gt;
    &lt;/parameter&gt;

    &lt;!-- You don't want to many idle connections hanging around
         if you can avoid it, only enough to soak up a spike in
         the load --&gt;

    &lt;parameter&gt;
      &lt;name&gt;maxIdle&lt;/name&gt;
      &lt;value&gt;5&lt;/value&gt;
    &lt;/parameter&gt;

    &lt;!-- Don't use autoReconnect=true, it's going away eventually
         and it's a crutch for older connection pools that couldn't
         test connections. You need to decide if your application is
         supposed to deal with SQLExceptions (hint, it should), and
         how much of a performance penalty you're willing to pay
         to ensure 'freshness' of the connection --&gt;

    &lt;parameter&gt;
      &lt;name&gt;validationQuery&lt;/name&gt;
      &lt;value&gt;SELECT 1&lt;/value&gt;
    &lt;/parameter&gt;

   &lt;!-- The most conservative approach is to test connections
        before they're given to your application. For most applications
        this is okay, the query used above is very small and takes
        no real server resources to process, other than the time used
        to traverse the network.

        If you have a high-load application you'll need to rely on
        something else. --&gt;

    &lt;parameter&gt;
      &lt;name&gt;testOnBorrow&lt;/name&gt;
      &lt;value&gt;true&lt;/value&gt;
    &lt;/parameter&gt;

   &lt;!-- Otherwise, or in addition to testOnBorrow, you can test
        while connections are sitting idle --&gt;

    &lt;parameter&gt;
      &lt;name&gt;testWhileIdle&lt;/name&gt;
      &lt;value&gt;true&lt;/value&gt;
    &lt;/parameter&gt;

    &lt;!-- You have to set this value, otherwise even though
         you've asked connections to be tested while idle,
         the idle evicter thread will never run --&gt;

    &lt;parameter&gt;
      &lt;name&gt;timeBetweenEvictionRunsMillis&lt;/name&gt;
      &lt;value&gt;10000&lt;/value&gt;
    &lt;/parameter&gt;

    &lt;!-- Don't allow connections to hang out idle too long,
         never longer than what wait_timeout is set to on the
         server...A few minutes or even fraction of a minute
         is sometimes okay here, it depends on your application
         and how much spikey load it will see --&gt;

    &lt;parameter&gt;
      &lt;name&gt;minEvictableIdleTimeMillis&lt;/name&gt;
      &lt;value&gt;60000&lt;/value&gt;
    &lt;/parameter&gt;

    &lt;!-- Username and password used when connecting to MySQL --&gt;

    &lt;parameter&gt;
     &lt;name&gt;username&lt;/name&gt;
     &lt;value&gt;someuser&lt;/value&gt;
    &lt;/parameter&gt;

    &lt;parameter&gt;
     &lt;name&gt;password&lt;/name&gt;
     &lt;value&gt;somepass&lt;/value&gt;
    &lt;/parameter&gt;

    &lt;!-- Class name for the Connector/J driver --&gt;

    &lt;parameter&gt;
       &lt;name&gt;driverClassName&lt;/name&gt;
       &lt;value&gt;com.mysql.jdbc.Driver&lt;/value&gt;
    &lt;/parameter&gt;

    &lt;!-- The JDBC connection url for connecting to MySQL, notice
         that if you want to pass any other MySQL-specific parameters
         you should pass them here in the URL, setting them using the
         parameter tags above will have no effect, you will also
         need to use &amp;amp; to separate parameter values as the
         ampersand is a reserved character in XML --&gt;

    &lt;parameter&gt;
      &lt;name&gt;url&lt;/name&gt;
      &lt;value&gt;jdbc:mysql://localhost:3306/test&lt;/value&gt;
    &lt;/parameter&gt;

  &lt;/ResourceParams&gt;
&lt;/Context&gt;</pre><p>In general, you should follow the installation instructions that
        come with your version of Tomcat, as the way you configure datasources
        in Tomcat changes from time-to-time, and unfortunately if you use the
        wrong syntax in your XML file, you will most likely end up with an
        exception similar to the following:</p><pre class="programlisting">Error: java.sql.SQLException: Cannot load JDBC driver class 'null ' SQL
state: null </pre></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="cj-jboss-config"></a>1.4.3.&nbsp;Using Connector/J with JBoss</h3></div></div><div></div></div><p></p><p>These instructions cover JBoss-4.x. To make the JDBC driver
        classes available to the application server, copy the .jar file that
        comes with Connector/J to the <tt class="filename">lib</tt> directory for
        your server configuration (which is usually called
        "<tt class="filename">default</tt>"). Then, in the same configuration
        directory, in the subdirectory named "deploy", create a datasource
        configuration file that ends with "-ds.xml", which tells JBoss to
        deploy this file as a JDBC Datasource. The file should have the
        following contents:</p><pre class="programlisting">&lt;datasources&gt;
    &lt;local-tx-datasource&gt;
        &lt;!-- This connection pool will be bound into JNDI with the name
             "java:/MySQLDB" --&gt;

        &lt;jndi-name&gt;MySQLDB&lt;/jndi-name&gt;
        &lt;connection-url&gt;jdbc:mysql://localhost:3306/dbname&lt;/connection-url&gt;
        &lt;driver-class&gt;com.mysql.jdbc.Driver&lt;/driver-class&gt;
        &lt;user-name&gt;user&lt;/user-name&gt;
        &lt;password&gt;pass&lt;/password&gt;

        &lt;min-pool-size&gt;5&lt;/min-pool-size&gt;

        &lt;!-- Don't set this any higher than max_connections on your
         MySQL server, usually this should be a 10 or a few 10's
         of connections, not hundreds or thousands --&gt;

        &lt;max-pool-size&gt;20&lt;/max-pool-size&gt;

        &lt;!-- Don't allow connections to hang out idle too long,
         never longer than what wait_timeout is set to on the
         server...A few minutes is usually okay here,
         it depends on your application
         and how much spikey load it will see --&gt;

        &lt;idle-timeout-minutes&gt;5&lt;/idle-timeout-minutes&gt;

        &lt;!-- If you're using Connector/J 3.1.8 or newer, you can use
             our implementation of these to increase the robustness
             of the connection pool. --&gt;

        &lt;exception-sorter-class-name&gt;com.mysql.jdbc.integration.jboss.ExtendedMysqlExceptionSorter&lt;/exception-sorter-class-name&gt;
        &lt;valid-connection-checker-class-name&gt;com.mysql.jdbc.integration.jboss.MysqlValidConnectionChecker&lt;/valid-connection-checker-class-name&gt;

    &lt;/local-tx-datasource&gt;
&lt;/datasources&gt; </pre></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="cj-troubleshooting"></a>1.5.&nbsp;Diagnosing Connector/J Problems</h2></div></div><div></div></div><p></p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="cj-faq"></a>1.5.1.&nbsp;Common Problems and Solutions</h3></div></div><div></div></div><p>There are a few issues that seem to be commonly encountered
        often by users of MySQL Connector/J. This section deals with their
        symptoms, and their resolutions. If you have further issues, see the
        "SUPPORT" section.</p><div class="qandaset"><dl><dt>1.5.1.1. <a href="#N10A44">When I try to connect to the database with MySQL
              Connector/J, I get the following exception:</a></dt><dt>1.5.1.2. <a href="#N10A65">My application throws a SQLException 'No Suitable Driver'.
              Why is this happening?</a></dt><dt>1.5.1.3. <a href="#N10A6C">I'm trying to use MySQL Connector/J in an applet or
              application and I get an exception similar to:</a></dt><dt>1.5.1.4. <a href="#N10A7C">I have a
              servlet/application that works fine for a day, and then stops
              working overnight</a></dt><dt>1.5.1.5. <a href="#N10A90">I'm trying to use JDBC-2.0 updatable result sets, and I
              get an exception saying my result set is not updatable.</a></dt></dl><table summary="Q and A Set" border="0"><col align="left" width="1%"><tbody><tr class="question"><td valign="top" align="left"><a name="N10A44"></a><a name="N10A45"></a><b>1.5.1.1. </b></td><td valign="top" align="left"><p>When I try to connect to the database with MySQL
              Connector/J, I get the following exception:</p><pre class="screen">SQLException: Server configuration denies access to data source
SQLState: 08001
VendorError: 0</pre><p>What's going on? I can connect just fine with the MySQL
              command-line client.</p></td></tr><tr class="answer"><td valign="top" align="left"><b></b></td><td valign="top" align="left"><p>MySQL Connector/J must use TCP/IP sockets to connect to
              MySQL, as Java does not support Unix Domain Sockets. Therefore,
              when MySQL Connector/J connects to MySQL, the security manager
              in MySQL server will use its grant tables to determine whether
              or not the connection should be allowed.</p><p>You must add grants to allow this to happen. The following
              is an example of how to do this (but not the most
              secure).</p><p>From the mysql command-line client, logged in as a user
              that can grant privileges, issue the following command:</p><pre class="screen">GRANT ALL PRIVILEGES ON [dbname].* to
                '[user]'@'[hostname]' identified by
                '[password]'</pre><p>replacing [dbname] with the name of your database, [user]
              with the user name, [hostname] with the host that MySQL
              Connector/J will be connecting from, and [password] with the
              password you want to use. Be aware that RedHat Linux is broken
              with respect to the hostname portion for the case when you are
              connecting from localhost. You need to use
              "localhost.localdomain" for the [hostname] value in this case.
              Follow this by issuing the "FLUSH PRIVILEGES" command.</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>Testing your connectivity with the "mysql" command-line
                client will not work unless you add the "--host" flag, and use
                something other than "localhost" for the host. The "mysql"
                command-line client will use Unix domain sockets if you use
                the special hostname "localhost". If you are testing
                connectivity to "localhost", use "127.0.0.1" as the hostname
                instead.</p></div><div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Warning</h3><p>If you don't understand what the 'GRANT' command does,
                or how it works, you should read and understand the <a href="http://www.mysql.com/doc/en/Privilege_system.html" target="_top">'General
                Security Issues and the MySQL Access Privilege System'</a>
                section of the MySQL manual before attempting to change
                privileges.</p><p>Changing privileges and permissions improperly in MySQL
                can potentially cause your server installation to not have
                optimal security properties.</p></div></td></tr><tr class="question"><td valign="top" align="left"><a name="N10A65"></a><a name="N10A66"></a><b>1.5.1.2. </b></td><td valign="top" align="left"><p>My application throws a SQLException 'No Suitable Driver'.
              Why is this happening?</p></td></tr><tr class="answer"><td valign="top" align="left"><b></b></td><td valign="top" align="left"><p>One of two things are happening. Either the driver is not
              in your CLASSPATH (see the "INSTALLATION" section above), or
              your URL format is incorrect (see "Developing Applications with
              MySQL Connector/J").</p></td></tr><tr class="question"><td valign="top" align="left"><a name="N10A6C"></a><a name="N10A6D"></a><b>1.5.1.3. </b></td><td valign="top" align="left"><p>I'm trying to use MySQL Connector/J in an applet or
              application and I get an exception similar to:</p><pre class="screen">SQLException: Cannot connect to MySQL server on host:3306.
Is there a MySQL server running on the machine/port you
are trying to connect to?

(java.security.AccessControlException)
SQLState: 08S01
VendorError: 0 </pre></td></tr><tr class="answer"><td valign="top" align="left"><b></b></td><td valign="top" align="left"><p>Either you're running an Applet, your MySQL server has
              been installed with the "--skip-networking" option set, or your
              MySQL server has a firewall sitting in front of it.</p><p>Applets can only make network connections back to the
              machine that runs the web server that served the .class files
              for the applet. This means that MySQL must run on the same
              machine (or you must have some sort of port re-direction) for
              this to work. This also means that you will not be able to test
              applets from your local file system, you must always deploy them
              to a web server.</p><p>MySQL Connector/J can only communicate with MySQL using
              TCP/IP, as Java does not support Unix domain sockets. TCP/IP
              communication with MySQL might be affected if MySQL was started
              with the "--skip-networking" flag, or if it is
              firewalled.</p><p>If MySQL has been started with the "--skip-networking"
              option set (the Debian Linux package of MySQL server does this
              for example), you need to comment it out in the file
              /etc/mysql/my.cnf or /etc/my.cnf. Of course your my.cnf file
              might also exist in the "data" directory of your MySQL server,
              or anywhere else (depending on how MySQL was compiled for your
              system). Binaries created by MySQL AB always look in /etc/my.cnf
              and [datadir]/my.cnf. If your MySQL server has been firewalled,
              you will need to have the firewall configured to allow TCP/IP
              connections from the host where your Java code is running to the
              MySQL server on the port that MySQL is listening to (by default,
              3306).</p></td></tr><tr class="question"><td valign="top" align="left"><a name="N10A7C"></a><a name="N10A7D"></a><b>1.5.1.4. </b></td><td valign="top" align="left"><p><a name="connector_j_wait_timeout_q_and_a"></a>I have a
              servlet/application that works fine for a day, and then stops
              working overnight</p></td></tr><tr class="answer"><td valign="top" align="left"><b></b></td><td valign="top" align="left"><p>MySQL closes connections after 8 hours of inactivity. You
              either need to use a connection pool that handles stale
              connections or use the "autoReconnect" parameter (see
              "Developing Applications with MySQL Connector/J").</p><p>Also, you should be catching SQLExceptions in your
              application and dealing with them, rather than propagating them
              all the way until your application exits, this is just good
              programming practice. MySQL Connector/J will set the SQLState
              (see java.sql.SQLException.getSQLState() in your APIDOCS) to
              "08S01" when it encounters network-connectivity issues during
              the processing of a query. Your application code should then
              attempt to re-connect to MySQL at this point.</p><p>The following (simplistic) example shows what code that
              can handle these exceptions might look like:</p><p><div class="example"><a name="N10A89"></a><p class="title"><b>Example&nbsp;1.13.&nbsp;Example of
                  transaction with retry logic</b></p><pre class="programlisting">public void doBusinessOp() throws SQLException {
        Connection conn = null;
        Statement stmt = null;
        ResultSet rs = null;

        //
        // How many times do you want to retry the transaction
        // (or at least _getting_ a connection)?
        //
        int retryCount = 5;

        boolean transactionCompleted = false;

        do {
            try {
                conn = getConnection(); // assume getting this from a
                                        // javax.sql.DataSource, or the
                                        // java.sql.DriverManager

                conn.setAutoCommit(false);

                //
                // Okay, at this point, the 'retry-ability' of the
                // transaction really depends on your application logic,
                // whether or not you're using autocommit (in this case
                // not), and whether you're using transacational storage
                // engines
                //
                // For this example, we'll assume that it's _not_ safe
                // to retry the entire transaction, so we set retry count
                // to 0 at this point
                //
                // If you were using exclusively transaction-safe tables,
                // or your application could recover from a connection going
                // bad in the middle of an operation, then you would not
                // touch 'retryCount' here, and just let the loop repeat
                // until retryCount == 0.
                //
                retryCount = 0;

                stmt = conn.createStatement();

                String query = "SELECT foo FROM bar ORDER BY baz";

                rs = stmt.executeQuery(query);

                while (rs.next()) {
                }

                rs.close();
                rs = null;

                stmt.close();
                stmt = null;

                conn.commit();
                conn.close();
                conn = null;

                transactionCompleted = true;
            } catch (SQLException sqlEx) {

                //
                // The two SQL states that are 'retry-able' are 08S01
                // for a communications error, and 41000 for deadlock.
                //
                // Only retry if the error was due to a stale connection,
                // communications problem or deadlock
                //

                String sqlState = sqlEx.getSQLState();

                if ("08S01".equals(sqlState) || "41000".equals(sqlState)) {
                    retryCount--;
                } else {
                    retryCount = 0;
                }
            } finally {
                if (rs != null) {
                    try {
                        rs.close();
                    } catch (SQLException sqlEx) {
                        // You'd probably want to log this . . .
                    }
                }

                if (stmt != null) {
                    try {
                        stmt.close();
                    } catch (SQLException sqlEx) {
                        // You'd probably want to log this as well . . .
                    }
                }

                if (conn != null) {
                    try {
                        //
                        // If we got here, and conn is not null, the
                        // transaction should be rolled back, as not
                        // all work has been done

                        try {
                            conn.rollback();
                        } finally {
                            conn.close();
                        }
                    } catch (SQLException sqlEx) {
                        //
                        // If we got an exception here, something
                        // pretty serious is going on, so we better
                        // pass it up the stack, rather than just
                        // logging it. . .

                        throw sqlEx;
                    }
                }
            }
        } while (!transactionCompleted &amp;&amp; (retryCount &gt; 0));
    }</pre></div></p></td></tr><tr class="question"><td valign="top" align="left"><a name="N10A90"></a><a name="N10A91"></a><b>1.5.1.5. </b></td><td valign="top" align="left"><p>I'm trying to use JDBC-2.0 updatable result sets, and I
              get an exception saying my result set is not updatable.</p></td></tr><tr class="answer"><td valign="top" align="left"><b></b></td><td valign="top" align="left"><p>Because MySQL does not have row identifiers, MySQL
              Connector/J can only update result sets that have come from
              queries on tables that have at least one primary key, the query
              must select all of the primary key(s) and the query can only
              span one table (i.e. no joins). This is outlined in the JDBC
              specification.</p></td></tr></tbody></table></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="cj-reporting-bugs"></a>1.5.2.&nbsp;How to Report Bugs or Problems</h3></div></div><div></div></div><p>The normal place to report bugs is <a href="http://bugs.mysql.com/" target="_top">http://bugs.mysql.com/</a>, which is
        the address for our bugs database. This database is public, and can be
        browsed and searched by anyone. If you log in to the system, you will
        also be able to enter new reports.</p><p>If you have found a sensitive security bug in MySQL, you can
        send email to <a href="mailto:security@mysql.com" target="_top">security@mysql.com</a>.</p><p>Writing a good bug report takes patience, but doing it right the
        first time saves time both for us and for yourself. A good bug report,
        containing a full test case for the bug, makes it very likely that we
        will fix the bug in the next release.</p><p>This section will help you write your report correctly so that
        you don't waste your time doing things that may not help us much or at
        all.</p><p>If you have a repeatable bug report, please report it to the
        bugs database at <a href="???" target="_top">http://bugs.mysql.com/</a>.</p><p>Any bug that we are able to repeat has a high chance of being
        fixed in the next MySQL release.</p><p>To report other problems, you can use one of the MySQL mailing
        lists.</p><p>Remember that it is possible for us to respond to a message
        containing too much information, but not to one containing too little.
        People often omit facts because they think they know the cause of a
        problem and assume that some details don't matter.</p><p>A good principle is this: If you are in doubt about stating
        something, state it. It is faster and less troublesome to write a
        couple more lines in your report than to wait longer for the answer if
        we must ask you to provide information that was missing from the
        initial report.</p><p>The most common errors made in bug reports are (a) not including
        the version number of Connector/J or MySQL used, and (b) not fully
        describing the platform on which Connector/J is installed (including
        the JVM version, and the platform type and version number that MySQL
        itself is installed on).</p><p>This is highly relevant information, and in 99 cases out of 100,
        the bug report is useless without it. Very often we get questions
        like, ``Why doesn't this work for me?'' Then we find that the feature
        requested wasn't implemented in that MySQL version, or that a bug
        described in a report has already been fixed in newer MySQL
        versions.</p><p>Sometimes the error is platform-dependent; in such cases, it is
        next to impossible for us to fix anything without knowing the
        operating system and the version number of the platform.</p><p>If at all possible, you should create a repeatable, stanalone
        testcase that doesn't involve any third-party classes.</p><p>To streamline this process, we ship a base class for testcases
        with Connector/J, named
        '<tt class="classname">com.mysql.jdbc.util.BaseBugReport</tt>'. To create
        a testcase for Connector/J using this class, create your own class
        that inherits from
        <tt class="classname">com.mysql.jdbc.util.BaseBugReport</tt> and override
        the methods <tt class="methodname">setUp()</tt>,
        <tt class="methodname">tearDown()</tt> and
        <tt class="methodname">runTest</tt>().</p><p>In the <tt class="methodname">setUp()</tt> method, create code that
        creates your tables, and populates them with any data needed to
        demonstrate the bug.</p><p>In the <tt class="methodname">runTest</tt>() method, create code
        that demonstrates the bug using the tables and data you created in the
        'setUp' method.</p><p>In the <tt class="methodname">tearDown()</tt> method, drop any
        tables you created in the <tt class="methodname">setUp()</tt>
        method.</p><p>In any of the above three methods, you should use one of the
        variants of the <tt class="methodname">getConnection</tt>() method to
        create a JDBC connection to MySQL:</p><p><div class="itemizedlist"><ul type="disc"><li><p>getConnection() - Provides a connection to the JDBC URL
              specified in getUrl(). If a connection already exists, that
              connection is returned, otherwise a new connection is
              created.</p></li><li><p>getNewConnection() - Use this if you need to get a new
              connection for your bug report (i.e. there's more than one
              connection involved).</p></li><li><p>getConnection(String url) - Returns a connection using the
              given URL.</p></li><li><p>getConnection(String url, Properties props) - Returns a
              connection using the given URL and properties.</p></li></ul></div>If you need to use a JDBC URL that is different than
        'jdbc:mysql:///test', then override the method
        <tt class="methodname">getUrl()</tt> as well.</p><p>Use the <tt class="methodname">assertTrue(boolean expression)</tt>
        and <tt class="methodname">assertTrue(String failureMessage, boolean
        expression)</tt> methods to create conditions that must be met
        in your testcase demonstrating the behavior you are expecting (vs. the
        behavior you are observing, which is why you are most likely filing a
        bug report).</p><p>Finally, create a <tt class="methodname">main</tt>() method that
        creates a new instance of your testcase, and calls the
        <tt class="methodname">run</tt> method: <pre class="programlisting">public static void main(String[] args) throws Exception {
      new MyBugReport().run();
 }</pre> Once you have finished your testcase, and have verified
        that it demonstrates the bug you are reporting, upload it with your
        bug report to <a href="http://bugs.mysql.com/" target="_top">http://bugs.mysql.com/</a>.</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="cj-changelog"></a>1.6.&nbsp;Changelog</h2></div></div><div></div></div><pre class="programlisting"># Changelog
# $Id: CHANGES,v 1.38.4.206 2005/05/12 15:25:54 mmatthews Exp $

05-17-05 - Version 3.2.1-alpha

    - Autoreconnect functionality (i.e. autoReconnect=true) is now deprecated.
      An exception will be thrown if you try and use it, use 
      'enableDeprecatedAutoreconnect=true' to still use autoReconnect. However
      this feature will be removed in Connector/J 3.3, see the manual for 
      solutions that don't require autoReconnect to be used.

    - Driver now checks if server variable 'init_connect' is set, and if so
      checks autocommit setting, and applies it.
  
    - If connected to server &gt; 5.0.x, and Statement.setFetchSize( &gt; 0), the
      driver will try and use server prepared statements and fetch
      statements using result set 'cursors'.
  
    - ServerPreparedStatements now correctly 'stream' BLOB/CLOB data to the
      server. You can configure the threshold chunk size using the
      JDBC URL property 'blobSendChunkSize' (the default is one megabyte).
  
    - Support sql mode NO_BACKSLASH_ESCAPES with non-server-side prepared
      statements.

12-23-04 - Version 3.2.0-alpha

    - Fixed incorrect return values from DatabaseMetaData.supportsCatalogIn*().
    
    - Support for 'cursor' based result sets when using ServerPreparedStatements
      and MySQL 5.0 or newer. Result set needs to be forward-only, and a non-zero
      fetch size for this feature to be enabled.
      
    - Refactoring of where logic for prepared statement, server-prepared 
      statement lives.
      
06-22-05 - Version 3.1.9-stable

    - Overhaul of character set configuration, everything now
      lives in a properties file.
  
    - Driver now correctly uses CP932 if available on the server
      for Windows-31J, CP932 and MS932 java encoding names, 
      otherwise it resorts to SJIS, which is only a close 
      approximation. Currently only MySQL-5.0.3 and newer (and
      MySQL-4.1.12 or .13, depending on when the character set
      gets backported) can reliably support any variant of CP932.

    - Fixed BUG#9064 - com.mysql.jdbc.PreparedStatement.ParseInfo 
      does unnecessary call to toCharArray().

    - Fixed Bug#10144 - Memory leak in ServerPreparedStatement if 
      serverPrepare() fails.
 
    - Actually write manifest file to correct place so it ends up
      in the binary jar file.

    - Added "createDatabaseIfNotExist" property (default is "false"),
      which will cause the driver to ask the server to create the 
      database specified in the URL if it doesn't exist. You must have
      the appropriate privileges for database creation for this to
      work.

    - Fixed BUG#10156 - Unsigned SMALLINT treated as signed for ResultSet.getInt(),
      fixed all cases for UNSIGNED integer values and server-side prepared statements,
      as well as ResultSet.getObject() for UNSIGNED TINYINT.
 
    - Fixed BUG#10155, double quotes not recognized when parsing 
      client-side prepared statements.
  
    - Made enableStreamingResults() visible on 
      com.mysql.jdbc.jdbc2.optional.StatementWrapper.
  
    - Made ServerPreparedStatement.asSql() work correctly so auto-explain
      functionality would work with server-side prepared statements.
  
    - Made JDBC2-compliant wrappers public in order to allow access to
      vendor extensions.
  
    - Cleaned up logging of profiler events, moved code to dump a profiler
      event as a string to com.mysql.jdbc.log.LogUtils so that third
      parties can use it.
  
    - DatabaseMetaData.supportsMultipleOpenResults() now returns true. The
      driver has supported this for some time, DBMD just missed that fact.
  
    - Fixed BUG#10310 - Driver doesn't support {?=CALL(...)} for calling
      stored functions. This involved adding support for function retrieval
      to DatabaseMetaData.getProcedures() and getProcedureColumns() as well.
      
    - Fixed BUG#10485, SQLException thrown when retrieving YEAR(2) 
      with ResultSet.getString(). The driver will now always treat YEAR types
      as java.sql.Dates and return the correct values for getString(). 
      Alternatively, the "yearIsDateType" connection property can be set to
      "false" and the values will be treated as SHORTs.
  
    - The datatype returned for TINYINT(1) columns when "tinyInt1isBit=true" 
      (the default) can be switched between Types.BOOLEAN and Types.BIT
      using the new configuration property "transformedBitIsBoolean", which
      defaults to "false". If set to "false" (the default), 
      DatabaseMetaData.getColumns() and ResultSetMetaData.getColumnType() 
      will return Types.BOOLEAN for TINYINT(1) columns. If "true", 
      Types.BOOLEAN will be returned instead. Irregardless of this configuration
      property, if "tinyInt1isBit" is enabled, columns with the type TINYINT(1)
      will be returned as java.lang.Boolean instances from 
      ResultSet.getObject(..), and ResultSetMetaData.getColumnClassName()
      will return "java.lang.Boolean".

    - Fixed BUG#10496 - SQLException is thrown when using property 
      "characterSetResults" with cp932 or eucjpms.
      
    - Reorganized directory layout, sources now in "src" folder,
      don't pollute parent directory when building, now output goes
      to "./build", distribution goes to "./dist".
      
    - Added support/bug hunting feature that generates .sql test
      scripts to STDERR when "autoGenerateTestcaseScript" is set
      to "true".
      
    - Fixed BUG#10850 - 0-length streams not sent to server when
      using server-side prepared statements.
    
    - Setting "cachePrepStmts=true" now causes the Connection to also 
      cache the check the driver performs to determine if a prepared 
      statement can be server-side or not, as well as caches server-side
      prepared statements for the lifetime of a connection. As before,
      the "prepStmtCacheSize" parameter controls the size of these
      caches.
      
    - Try to handle OutOfMemoryErrors more gracefully. Although not
      much can be done, they will in most cases close the connection
      they happened on so that further operations don't run into 
      a connection in some unknown state. When an OOM has happened, 
      any further operations on the connection will fail with a 
      "Connection closed" exception that will also list the OOM exception
      as the reason for the implicit connection close event.
      
    - Don't send COM_RESET_STMT for each execution of a server-side
      prepared statement if it isn't required.
      
    - Driver detects if you're running MySQL-5.0.7 or later, and does
      not scan for "LIMIT ?[,?]" in statements being prepared, as the
      server supports those types of queries now.
      
    - Fixed BUG#11115, Varbinary data corrupted when using server-side
      prepared statements and ResultSet.getBytes().
      
    - Connection.setCatalog() is now aware of the "useLocalSessionState"
      configuration property, which when set to true will prevent
      the driver from sending "USE ..." to the server if the requested
      catalog is the same as the current catalog.
      
    - Added the following configuration bundles, use one or many via
      the "useConfigs" configuration property:
    
        * maxPerformance -- maximum performance without being reckless
        * solarisMaxPerformance -- maximum performance for Solaris,
                                   avoids syscalls where it can
        * 3-0-Compat -- Compatibility with Connector/J 3.0.x functionality
        
    - Added "maintainTimeStats" configuration property (defaults to "true"),
      which tells the driver whether or not to keep track of the last query time
      and the last successful packet sent to the server's time. If set to
      false, removes two syscalls per query.
    
    - Fixed BUG#11259, autoReconnect ping causes exception on connection 
      startup.
      
    - Fixed BUG#11360 Connector/J dumping query into SQLException twice
    
    - Fixed PreparedStatement.setClob() not accepting null as a parameter.
    
    - Fixed BUG#11411 - Production package doesn't include JBoss integration 
      classes.
      
    - Removed nonsensical "costly type conversion" warnings when using 
      usage advisor.


04-14-05 - Version 3.1.8-stable

    - Fixed DatabaseMetaData.getTables() returning views when they were
      not asked for as one of the requested table types.

    - Added support for new precision-math DECIMAL type in MySQL &gt;= 5.0.3.

    - Fixed ResultSet.getTime() on a NULL value for server-side prepared
      statements throws NPE.

    - Made Connection.ping() a public method.

    - Fixed Bug#8868, DATE_FORMAT() queries returned as BLOBs from getObject().

    - ServerPreparedStatements now correctly 'stream' BLOB/CLOB data to the
      server. You can configure the threshold chunk size using the
      JDBC URL property 'blobSendChunkSize' (the default is one megabyte).

    - BlobFromLocator now uses correct identifier quoting when generating
      prepared statements.

    - Server-side session variables can be preset at connection time by
      passing them as a comma-delimited list for the connection property
      'sessionVariables'.

    - Fixed regression in ping() for users using autoReconnect=true.

    - Fixed BUG#9040 - PreparedStatement.addBatch() doesn't work with server-side
      prepared statements and streaming BINARY data.

    - Fixed BUG#8800 - DBMD.supportsMixedCase*Identifiers() returns wrong
      value on servers running on case-sensitive filesystems.

    - Fixed BUG#9206, can not use 'UTF-8' for characterSetResults
      configuration property.

    - Fixed BUG#9236, a continuation of BUG#8868, where functions used in queries
      that should return non-string types when resolved by temporary tables suddenly
      become opaque binary strings (work-around for server limitation). Also fixed
      fields with type of CHAR(n) CHARACTER SET BINARY to return correct/matching
      classes for RSMD.getColumnClassName() and ResultSet.getObject().

    - Fixed BUG#8792 - DBMD.supportsResultSetConcurrency() not returning
      true for forward-only/read-only result sets (we obviously support this).

    - Fixed BUG#8803, 'DATA_TYPE' column from DBMD.getBestRowIdentifier()
      causes ArrayIndexOutOfBoundsException when accessed (and in fact, didn't
      return any value).

    - Check for empty strings ('') when converting char/varchar column data to numbers,
      throw exception if 'emptyStringsConvertToZero' configuration property is set
      to 'false' (for backwards-compatibility with 3.0, it is now set to 'true'
      by default, but will most likely default to 'false' in 3.2).

    - Fixed BUG#9320 - PreparedStatement.getMetaData() inserts blank row in database
      under certain conditions when not using server-side prepared statements.

    - Connection.canHandleAsPreparedStatement() now makes 'best effort' to distinguish
      LIMIT clauses with placeholders in them from ones without in order to have fewer
      false positives when generating work-arounds for statements the server cannot
      currently handle as server-side prepared statements.

    - Fixed build.xml to not compile log4j logging if log4j not available.

    - Added support for the c3p0 connection pool's (http://c3p0.sf.net/)
      validation/connection checker interface which uses the lightweight
      'COM_PING' call to the server if available. To use it, configure your
      c3p0 connection pool's 'connectionTesterClassName' property to use
      'com.mysql.jdbc.integration.c3p0.MysqlConnectionTester'.

    - Better detection of LIMIT inside/outside of quoted strings so that
      the driver can more correctly determine whether a prepared statement
      can be prepared on the server or not.

    - Fixed BUG#9319 - Stored procedures with same name in
      different databases confuse the driver when it tries to determine
      parameter counts/types.

    - Added finalizers to ResultSet and Statement implementations to be JDBC
      spec-compliant, which requires that if not explicitly closed, these
      resources should be closed upon garbage collection.

    - Fixed BUG#9682 - Stored procedures with DECIMAL parameters with
      storage specifications that contained "," in them would fail.

    - PreparedStatement.setObject(int, Object, int type, int scale) now
      uses scale value for BigDecimal instances.

    - Fixed BUG#9704 - Statement.getMoreResults() could throw NPE when
      existing result set was .close()d.

    - The performance metrics feature now gathers information about
      number of tables referenced in a SELECT.

    - The logging system is now automatically configured. If the value has
      been set by the user, via the URL property "logger" or the system
      property "com.mysql.jdbc.logger", then use that, otherwise, autodetect
      it using the following steps:

         Log4j, if it's available,
         Then JDK1.4 logging,
         Then fallback to our STDERR logging.

    - Fixed BUG#9778, DBMD.getTables() shouldn't return tables if views
      are asked for, even if the database version doesn't support views.

    - Fixed driver not returning 'true' for '-1' when ResultSet.getBoolean()
      was called on result sets returned from server-side prepared statements.

    - Added a Manifest.MF file with implementation information to the .jar
      file.

    - More tests in Field.isOpaqueBinary() to distinguish opaque binary (i.e.
      fields with type CHAR(n) and CHARACTER SET BINARY) from output of
      various scalar and aggregate functions that return strings.

    - Fixed BUG#9917 - Should accept null for catalog (meaning use current)
      in DBMD methods, even though it's not JDBC-compliant for legacy's sake.
      Disable by setting connection property "nullCatalogMeansCurrent" to "false"
      (which will be the default value in C/J 3.2.x).

    - Fixed BUG#9769 - Should accept null for name patterns in DBMD (meaning "%"),
      even though it isn't JDBC compliant, for legacy's sake. Disable by setting
      connection property "nullNamePatternMatchesAll" to "false" (which will be
      the default value in C/J 3.2.x).

02-18-05 - Version 3.1.7-stable

    - Fixed BUG#7686, Timestamp key column data needed "_binary'"
      stripped for UpdatableResultSet.refreshRow().

    - Fixed BUG#7715 - Timestamps converted incorrectly to strings
      with Server-side prepared statements and updatable result sets.

    - Detect new sql_mode variable in string form (it used to be
      integer) and adjust quoting method for strings appropriately.

    - Added 'holdResultsOpenOverStatementClose' property (default is
      false), that keeps result sets open over statement.close() or new
      execution on same statement (suggested by Kevin Burton).

    - Fixed BUG#7952 -- Infinite recursion when 'falling back' to master
      in failover configuration.

    - Disable multi-statements (if enabled) for MySQL-4.1 versions prior
      to version 4.1.10 if the query cache is enabled, as the server
      returns wrong results in this configuration.

    - Fixed duplicated code in configureClientCharset() that prevented
      useOldUTF8Behavior=true from working properly.

    - Removed 'dontUnpackBinaryResults' functionality, the driver now
      always stores results from server-side prepared statements as-is
      from the server and unpacks them on demand.

    - Fixed BUG#8096 where emulated locators corrupt binary data
      when using server-side prepared statements.

    - Fixed synchronization issue with
      ServerPreparedStatement.serverPrepare() that could cause
      deadlocks/crashes if connection was shared between threads.

    - By default, the driver now scans SQL you are preparing via all
      variants of Connection.prepareStatement() to determine if it is a
      supported type of statement to prepare on the server side, and if
      it is not supported by the server, it instead prepares it as a
      client-side emulated prepared statement (BUG#4718). You can
      disable this by passing 'emulateUnsupportedPstmts=false' in your
      JDBC URL.

    - Remove _binary introducer from parameters used as in/out
      parameters in CallableStatement.

    - Always return byte[]s for output parameters registered as *BINARY.

    - Send correct value for 'boolean' "true" to server for
      PreparedStatement.setObject(n, "true", Types.BIT).

    - Fixed bug with Connection not caching statements from
      prepareStatement() when the statement wasn't a server-side
      prepared statement.

    - Choose correct 'direction' to apply time adjustments when both
      client and server are in GMT timezone when using
      ResultSet.get(..., cal) and PreparedStatement.set(...., cal).

    - Added 'dontTrackOpenResources' option (default is false, to be
      JDBC compliant), which helps with memory use for non-well-behaved
      apps (i.e applications which don't close Statements when they
      should).

    - Fixed BUG#8428 - ResultSet.getString() doesn't maintain format
      stored on server, bug fix only enabled when 'noDatetimeStringSync'
      property is set to 'true' (the default is 'false').

    - Fixed NPE in ResultSet.realClose() when using usage advisor and
      result set was already closed.

    - Fixed BUG#8487 - PreparedStatements not creating streaming result
      sets.

    - Don't pass NULL to String.valueOf() in
      ResultSet.getNativeConvertToString(), as it stringifies it (i.e.
      returns "null"), which is not correct for the method in question.

    - Fixed BUG#8484 - ResultSet.getBigDecimal() throws exception
      when rounding would need to occur to set scale. The driver now
      chooses a rounding mode of 'half up' if non-rounding
      BigDecimal.setScale() fails.

    - Added 'useLocalSessionState' configuration property, when set to
      'true' the JDBC driver trusts that the application is well-behaved
      and only sets autocommit and transaction isolation levels using
      the methods provided on java.sql.Connection, and therefore can
      manipulate these values in many cases without incurring
      round-trips to the database server.

    - Added enableStreamingResults() to Statement for connection pool
      implementations that check Statement.setFetchSize() for
      specification-compliant values. Call Statement.setFetchSize(&gt;=0)
      to disable the streaming results for that statement.

    - Added support for BIT type in MySQL-5.0.3. The driver will treat
      BIT(1-8) as the JDBC standard BIT type (which maps to
      java.lang.Boolean), as the server does not currently send enough
      information to determine the size of a bitfield when &lt; 9 bits are
      declared. BIT(&gt;9) will be treated as VARBINARY, and will return
      byte[] when getObject() is called.

12-23-04 - Version 3.1.6-stable

    - Fixed hang on SocketInputStream.read() with Statement.setMaxRows() and
      multiple result sets when driver has to truncate result set directly,
      rather than tacking a 'LIMIT n' on the end of it.

    - Fixed BUG#7026 - DBMD.getProcedures() doesn't respect catalog parameter.

12-02-04 - Version 3.1.5-gamma

    - Fix comparisons made between string constants and dynamic strings that
      are either toUpperCase()d or toLowerCase()d to use Locale.ENGLISH, as
      some locales 'override' case rules for English. Also use
      StringUtils.indexOfIgnoreCase() instead of .toUpperCase().indexOf(),
      avoids creating a very short-lived transient String instance.

    - Fixed BUG#5235 - Server-side prepared statements did not honor
      'zeroDateTimeBehavior' property, and would cause class-cast
      exceptions when using ResultSet.getObject(), as the all-zero string
      was always returned.

    - Fixed batched updates with server prepared statements weren't looking if
      the types had changed for a given batched set of parameters compared
      to the previous set, causing the server to return the error
      'Wrong arguments to mysql_stmt_execute()'.

    - Handle case when string representation of timestamp contains trailing '.'
      with no numbers following it.

    - Fixed BUG#5706 - Inefficient detection of pre-existing string instances
      in ResultSet.getNativeString().

    - Don't throw exceptions for Connection.releaseSavepoint().

    - Use a per-session Calendar instance by default when decoding dates
      from ServerPreparedStatements (set to old, less performant behavior by
      setting property 'dynamicCalendars=true').

    - Added experimental configuration property 'dontUnpackBinaryResults',
      which delays unpacking binary result set values until they're asked for,
      and only creates object instances for non-numerical values (it is set
      to 'false' by default). For some usecase/jvm combinations, this is
      friendlier on the garbage collector.

    - Fixed BUG#5729 - UNSIGNED BIGINT unpacked incorrectly from
      server-side prepared statement result sets.

    - Fixed BUG#6225 - ServerSidePreparedStatement allocating short-lived
      objects un-necessarily.

    - Removed un-wanted new Throwable() in ResultSet constructor due to bad
      merge (caused a new object instance that was never used for every result
      set created) - Found while profiling for BUG#6359.

    - Fixed too-early creation of StringBuffer in EscapeProcessor.escapeSQL(),
      also return String when escaping not needed (to avoid unnecssary object
      allocations). Found while profiling for BUG#6359.

    - Use null-safe-equals for key comparisons in updatable result sets.

    - Fixed BUG#6537, SUM() on Decimal with server-side prepared statement ignores
      scale if zero-padding is needed (this ends up being due to conversion to DOUBLE
      by server, which when converted to a string to parse into BigDecimal, loses all
      'padding' zeros).

    - Use DatabaseMetaData.getIdentifierQuoteString() when building DBMD
      queries.

    - Use 1MB packet for sending file for LOAD DATA LOCAL INFILE if that
      is &lt; 'max_allowed_packet' on server.

    - Fixed BUG#6399, ResultSetMetaData.getColumnDisplaySize() returns incorrect
      values for multibyte charsets.

    - Make auto-deserialization of java.lang.Objects stored in BLOBs
      configurable via 'autoDeserialize' property (defaults to 'false').

    - Re-work Field.isOpaqueBinary() to detect 'CHAR(n) CHARACTER SET BINARY'
      to support fixed-length binary fields for ResultSet.getObject().

    - Use our own implementation of buffered input streams to get around
      blocking behavior of java.io.BufferedInputStream. Disable this with
      'useReadAheadInput=false'.

    - Fixed BUG#6348, failing to connect to the server when one of the
      addresses for the given host name is IPV6 (which the server does
      not yet bind on). The driver now loops through _all_ IP addresses
      for a given host, and stops on the first one that accepts() a
      socket.connect().

09-04-04 - Version 3.1.4-beta

    - Fixed BUG#4510 - connector/j 3.1.3 beta does not handle integers
      correctly (caused by changes to support unsigned reads in
      Buffer.readInt() -&gt; Buffer.readShort()).

    - Added support in DatabaseMetaData.getTables() and getTableTypes()
      for VIEWs which are now available in MySQL server version 5.0.x.

    - Fixed BUG#4642 -- ServerPreparedStatement.execute*() sometimes
      threw ArrayIndexOutOfBoundsException when unpacking field metadata.

    - Optimized integer number parsing, enable 'old' slower integer parsing
      using JDK classes via 'useFastIntParsing=false' property.

    - Added 'useOnlyServerErrorMessages' property, which causes message text
      in exceptions generated by the server to only contain the text sent by
      the server (as opposed to the SQLState's 'standard' description, followed
      by the server's error message). This property is set to 'true' by default.

    - Fixed BUG#4689 - ResultSet.wasNull() does not work for primatives if a
      previous null was returned.

    - Track packet sequence numbers if enablePacketDebug=true, and throw an
      exception if packets received out-of-order.

    - Fixed BUG#4482, ResultSet.getObject() returns wrong type for strings
      when using prepared statements.

    - Calling MysqlPooledConnection.close() twice (even though an application
      error), caused NPE. Fixed.

    - Fixed BUG#5012 -- ServerPreparedStatements dealing with return of
      DECIMAL type don't work.

    - Fixed BUG#5032 -- ResultSet.getObject() doesn't return
      type Boolean for pseudo-bit types from prepared statements on 4.1.x
      (shortcut for avoiding extra type conversion when using binary-encoded
      result sets obscurred test in getObject() for 'pseudo' bit type)

    - You can now use URLs in 'LOAD DATA LOCAL INFILE' statements, and the
      driver will use Java's built-in handlers for retreiving the data and
      sending it to the server. This feature is not enabled by default,
      you must set the 'allowUrlInLocalInfile' connection property to 'true'.

    - The driver is more strict about truncation of numerics on
      ResultSet.get*(), and will throw a SQLException when truncation is
      detected. You can disable this by setting 'jdbcCompliantTruncation' to
      false (it is enabled by default, as this functionality is required
      for JDBC compliance).

    - Added three ways to deal with all-zero datetimes when reading them from
      a ResultSet, 'exception' (the default), which throws a SQLException
      with a SQLState of 'S1009', 'convertToNull', which returns NULL instead of
      the date, and 'round', which rounds the date to the nearest closest value
      which is '0001-01-01'.

    - Fixed ServerPreparedStatement to read prepared statement metadata off
      the wire, even though it's currently a placeholder instead of using
      MysqlIO.clearInputStream() which didn't work at various times because
      data wasn't available to read from the server yet. This fixes sporadic
      errors users were having with ServerPreparedStatements throwing
      ArrayIndexOutOfBoundExceptions.

    - Use com.mysql.jdbc.Message's classloader when loading resource bundle,
      should fix sporadic issues when the caller's classloader can't locate
      the resource bundle.

07-07-04 - Version 3.1.3-beta

    - Mangle output parameter names for CallableStatements so they
      will not clash with user variable names.

    - Added support for INOUT parameters in CallableStatements.

    - Fix for BUG#4119, null bitmask sent for server-side prepared
      statements was incorrect.

    - Use SQL Standard SQL states by default, unless 'useSqlStateCodes'
      property is set to 'false'.

    - Added packet debuging code (see the 'enablePacketDebug' property
      documentation).

    - Added constants for MySQL error numbers (publicly-accessible,
      see com.mysql.jdbc.MysqlErrorNumbers), and the ability to
      generate the mappings of vendor error codes to SQLStates
      that the driver uses (for documentation purposes).

    - Externalized more messages (on-going effort).

    - Fix for BUG#4311 - Error in retrieval of mediumint column with
      prepared statements and binary protocol.

    - Support new timezone variables in MySQL-4.1.3 when
      'useTimezone=true'

    - Support for unsigned numerics as return types from prepared statements.
      This also causes a change in ResultSet.getObject() for the 'bigint unsigned'
      type, which used to return BigDecimal instances, it now returns instances
      of java.lang.BigInteger.

06-09-04 - Version 3.1.2-alpha

    - Fixed stored procedure parameter parsing info when size was
      specified for a parameter (i.e. char(), varchar()).

    - Enabled callable statement caching via 'cacheCallableStmts'
      property.

    - Fixed case when no output parameters specified for a
      stored procedure caused a bogus query to be issued
      to retrieve out parameters, leading to a syntax error
      from the server.

    - Fixed case when no parameters could cause a NullPointerException
      in CallableStatement.setOutputParameters().

    - Removed wrapping of exceptions in MysqlIO.changeUser().

    - Fixed sending of split packets for large queries, enabled nio
      ability to send large packets as well.

    - Added .toString() functionality to ServerPreparedStatement,
      which should help if you're trying to debug a query that is
      a prepared statement (it shows SQL as the server would process).

    - Added 'gatherPerformanceMetrics' property, along with properties
      to control when/where this info gets logged (see docs for more
      info).

    - ServerPreparedStatements weren't actually de-allocating
      server-side resources when .close() was called.

    - Added 'logSlowQueries' property, along with property
      'slowQueriesThresholdMillis' to control when a query should
      be considered 'slow'.

    - Correctly map output parameters to position given in
      prepareCall() vs. order implied during registerOutParameter() -
      fixes BUG#3146.

    - Correctly detect initial character set for servers &gt;= 4.1.0

    - Cleaned up detection of server properties.

    - Support placeholder for parameter metadata for server &gt;= 4.1.2

    - Fix for BUG#3539 getProcedures() does not return any procedures in
      result set

    - Fix for BUG#3540 getProcedureColumns() doesn't work with wildcards
      for procedure name

    - Fixed BUG#3520 -- DBMD.getSQLStateType() returns incorrect value.

    - Added 'connectionCollation' property to cause driver to issue
      'set collation_connection=...' query on connection init if default
      collation for given charset is not appropriate.

    - Fixed DatabaseMetaData.getProcedures() when run on MySQL-5.0.0 (output of
    'show procedure status' changed between 5.0.1 and 5.0.0.

    - Fixed BUG#3804 -- getWarnings() returns SQLWarning instead of DataTruncation

    - Don't enable server-side prepared statements for server version 5.0.0 or 5.0.1,
    as they aren't compatible with the '4.1.2+' style that the driver uses (the driver
    expects information to come back that isn't there, so it hangs).

02-14-04 - Version 3.1.1-alpha

    - Fixed bug with UpdatableResultSets not using client-side
    prepared statements.

    - Fixed character encoding issues when converting bytes to
      ASCII when MySQL doesn't provide the character set, and
      the JVM is set to a multibyte encoding (usually affecting
      retrieval of numeric values).

    - Unpack 'unknown' data types from server prepared statements
      as Strings.

    - Implemented long data (Blobs, Clobs, InputStreams, Readers)
      for server prepared statements.

    - Implemented Statement.getWarnings() for MySQL-4.1 and newer
      (using 'SHOW WARNINGS').

    - Default result set type changed to TYPE_FORWARD_ONLY
      (JDBC compliance).

    - Centralized setting of result set type and concurrency.

    - Re-factored how connection properties are set and exposed
      as DriverPropertyInfo as well as Connection and DataSource
      properties.

    - Support for NIO. Use 'useNIO=true' on platforms that support
      NIO.

    - Support for SAVEPOINTs (MySQL &gt;= 4.0.14 or 4.1.1).

    - Support for mysql_change_user()...See the changeUser() method
      in com.mysql.jdbc.Connection.

    - Reduced number of methods called in average query to be more
      efficient.

    - Prepared Statements will be re-prepared on auto-reconnect. Any errors
      encountered are postponed until first attempt to re-execute the
      re-prepared statement.

    - Ensure that warnings are cleared before executing queries
      on prepared statements, as-per JDBC spec (now that we support
      warnings).

    - Support 'old' profileSql capitalization in ConnectionProperties.
      This property is deprecated, you should use 'profileSQL' if possible.

    - Optimized Buffer.readLenByteArray() to return shared empty byte array
      when length is 0.

    - Allow contents of PreparedStatement.setBlob() to be retained
      between calls to .execute*().

    - Deal with 0-length tokens in EscapeProcessor (caused by callable
      statement escape syntax).

    - Check for closed connection on delete/update/insert row operations in
      UpdatableResultSet.

    - Fix support for table aliases when checking for all primary keys in
      UpdatableResultSet.

    - Removed useFastDates connection property.

    - Correctly initialize datasource properties from JNDI Refs, including
      explicitly specified URLs.

    - DatabaseMetaData now reports supportsStoredProcedures() for
      MySQL versions &gt;= 5.0.0

    - Fixed stack overflow in Connection.prepareCall() (bad merge).

    - Fixed IllegalAccessError to Calendar.getTimeInMillis() in DateTimeValue
      (for JDK &lt; 1.4).

    - Fix for BUG#1673, where DatabaseMetaData.getColumns() is not
      returning correct column ordinal info for non '%' column name patterns.

    - Merged fix of datatype mapping from MySQL type 'FLOAT' to
      java.sql.Types.REAL from 3.0 branch.

    - Detect collation of column for RSMD.isCaseSensitive().

    - Fixed sending of queries &gt; 16M.

    - Added named and indexed input/output parameter support to CallableStatement.
      MySQL-5.0.x or newer.

    - Fixed NullPointerException in ServerPreparedStatement.setTimestamp(),
      as well as year and month descrepencies in
      ServerPreparedStatement.setTimestamp(), setDate().

    - Added ability to have multiple database/JVM targets for compliance
      and regression/unit tests in build.xml.

    - Fixed NPE and year/month bad conversions when accessing some
      datetime functionality in ServerPreparedStatements and their
      resultant result sets.

    - Display where/why a connection was implicitly closed (to
      aid debugging).

    - CommunicationsException implemented, that tries to determine
      why communications was lost with a server, and displays
      possible reasons when .getMessage() is called.

    - Fixed BUG#2359, NULL values for numeric types in binary
      encoded result sets causing NullPointerExceptions.

    - Implemented Connection.prepareCall(), and DatabaseMetaData.
      getProcedures() and getProcedureColumns().

    - Reset 'long binary' parameters in ServerPreparedStatement when
      clearParameters() is called, by sending COM_RESET_STMT to the
      server.

    - Merged prepared statement caching, and .getMetaData() support
      from 3.0 branch.

    - Fixed off-by-1900 error in some cases for
      years in TimeUtil.fastDate/TimeCreate() when unpacking results
      from server-side prepared statements.

    - Fixed BUG#2502 -- charset conversion issue in getTables().

    - Implemented multiple result sets returned from a statement
      or stored procedure.

    - Fixed BUG#2606 -- Server side prepared statements not returning
      datatype 'YEAR' correctly.

    - Enabled streaming of result sets from server-side prepared
      statements.

    - Fixed BUG#2623 -- Class-cast exception when using
      scrolling result sets and server-side prepared statements.

    - Merged unbuffered input code from 3.0.

    - Fixed ConnectionProperties that weren't properly exposed
      via accessors, cleaned up ConnectionProperties code.

    - Fixed BUG#2671, NULL fields not being encoded correctly in
      all cases in server side prepared statements.

    - Fixed rare buffer underflow when writing numbers into buffers
      for sending prepared statement execution requests.

    - Use DocBook version of docs for shipped versions of drivers.

02-18-03 - Version 3.1.0-alpha

    - Added 'requireSSL' property.

    - Added 'useServerPrepStmts' property (default 'false'). The
      driver will use server-side prepared statements when the
      server version supports them (4.1 and newer) when this
      property is set to 'true'. It is currently set to 'false'
      by default until all bind/fetch functionality has been
      implemented. Currently only DML prepared statements are
      implemented for 4.1 server-side prepared statements.

    - Track open Statements, close all when Connection.close()
      is called (JDBC compliance).

06-23-05 - Version 3.0.17-ga

    - Fixed BUG#5874, Timestamp/Time conversion goes in the wrong 'direction'
      when useTimeZone='true' and server timezone differs from client timezone.

    - Fixed BUG#7081, DatabaseMetaData.getIndexInfo() ignoring 'unique'
      parameter.

    - Support new protocol type 'MYSQL_TYPE_VARCHAR'.

    - Added 'useOldUTF8Behavoior' configuration property, which causes
      JDBC driver to act like it did with MySQL-4.0.x and earlier when
      the character encoding is 'utf-8' when connected to MySQL-4.1 or
      newer.

    - Fixed BUG#7316 - Statements created from a pooled connection were
      returning physical connection instead of logical connection when
      getConnection() was called.

    - Fixed BUG#7033 - PreparedStatements don't encode Big5 (and other
      multibyte) character sets correctly in static SQL strings.

    - Fixed BUG#6966, connections starting up failed-over (due to down master)
      never retry master.

    - Fixed BUG#7061, PreparedStatement.fixDecimalExponent() adding extra
      '+', making number unparseable by MySQL server.

    - Fixed BUG#7686, Timestamp key column data needed "_binary'" stripped for
      UpdatableResultSet.refreshRow().

    - Backported SQLState codes mapping from Connector/J 3.1, enable with
      'useSqlStateCodes=true' as a connection property, it defaults to
      'false' in this release, so that we don't break legacy applications (it
      defaults to 'true' starting with Connector/J 3.1).

    - Fixed BUG#7601, PreparedStatement.fixDecimalExponent() adding extra
      '+', making number unparseable by MySQL server.

    - Escape sequence {fn convert(..., type)} now supports ODBC-style types
      that are prepended by 'SQL_'.

    - Fixed duplicated code in configureClientCharset() that prevented
      useOldUTF8Behavior=true from working properly.

    - Handle streaming result sets with &gt; 2 billion rows properly by fixing
      wraparound of row number counter.

    - Fixed BUG#7607 - MS932, SHIFT_JIS and Windows_31J not recog. as
      aliases for sjis.

    - Fixed BUG#6549 (while fixing #7607), adding 'CP943' to aliases for
      sjis.

    - Fixed BUG#8064, which requires hex escaping of binary data when using
      multibyte charsets with prepared statements.

    - Fixed BUG#8812, NON_UNIQUE column from DBMD.getIndexInfo() returned
      inverted value.

    - Workaround for server BUG#9098 - default values of CURRENT_* for
      DATE/TIME/TIMESTAMP/TIMESTAMP columns can't be distinguished from
      'string' values, so UpdatableResultSet.moveToInsertRow() generates
      bad SQL for inserting default values.

    - Fixed BUG#8629 - 'EUCKR' charset is sent as 'SET NAMES euc_kr' which
      MySQL-4.1 and newer doesn't understand.

    - DatabaseMetaData.supportsSelectForUpdate() returns correct value based
      on server version.

    - Use hex escapes for PreparedStatement.setBytes() for double-byte charsets
      including 'aliases' Windows-31J, CP934, MS932.

    - Added support for the "EUC_JP_Solaris" character encoding, which maps
      to a MySQL encoding of "eucjpms" (backported from 3.1 branch). This only
      works on servers that support eucjpms, namely 5.0.3 or later.

11-15-04 - Version 3.0.16-ga

    - Re-issue character set configuration commands when re-using pooled
      connections and/or Connection.changeUser() when connected to MySQL-4.1
      or newer.

    - Fixed ResultSetMetaData.isReadOnly() to detect non-writable columns
      when connected to MySQL-4.1 or newer, based on existence of 'original'
      table and column names.

    - Fixed BUG#5664, ResultSet.updateByte() when on insert row
      throws ArrayOutOfBoundsException.

    - Fixed DatabaseMetaData.getTypes() returning incorrect (i.e. non-negative)
      scale for the 'NUMERIC' type.

    - Fixed BUG#6198, off-by-one bug in Buffer.readString(string).

    - Made TINYINT(1) -&gt; BIT/Boolean conversion configurable via 'tinyInt1isBit'
      property (default 'true' to be JDBC compliant out of the box).

    - Only set 'character_set_results' during connection establishment if
      server version &gt;= 4.1.1.

    - Fixed regression where useUnbufferedInput was defaulting to 'false'.

    - Fixed BUG#6231, ResultSet.getTimestamp() on a column with TIME in it
      fails.

09-04-04 - Version 3.0.15-production

    - Fixed BUG#4010 - StringUtils.escapeEasternUnicodeByteStream is still
      broken for GBK

    - Fixed BUG#4334 - Failover for autoReconnect not using port #'s for any
      hosts, and not retrying all hosts. (WARN: This required a change to
      the SocketFactory connect() method signature, which is now

       public Socket connect(String host, int portNumber, Properties props)

      therefore any third-party socket factories will have to be changed
      to support this signature.

    - Logical connections created by MysqlConnectionPoolDataSource will
      now issue a rollback() when they are closed and sent back to the pool.
      If your application server/connection pool already does this for you, you
      can set the 'rollbackOnPooledClose' property to false to avoid the
      overhead of an extra rollback().

    - Removed redundant calls to checkRowPos() in ResultSet.

    - Fixed BUG#4742, 'DOUBLE' mapped twice in DBMD.getTypeInfo().

    - Added FLOSS license exemption.

    - Fixed BUG#4808, calling .close() twice on a PooledConnection causes NPE.

    - Fixed BUG#4138 and BUG#4860, DBMD.getColumns() returns incorrect JDBC
      type for unsigned columns. This affects type mappings for all numeric
      types in the RSMD.getColumnType() and RSMD.getColumnTypeNames() methods
      as well, to ensure that 'like' types from DBMD.getColumns() match up
      with what RSMD.getColumnType() and getColumnTypeNames() return.

    - 'Production' - 'GA' in naming scheme of distributions.

    - Fix for BUG#4880, RSMD.getPrecision() returning 0 for non-numeric types
      (should return max length in chars for non-binary types, max length
      in bytes for binary types). This fix also fixes mapping of
      RSMD.getColumnType() and RSMD.getColumnTypeName() for the BLOB types based
      on the length sent from the server (the server doesn't distinguish between
      TINYBLOB, BLOB, MEDIUMBLOB or LONGBLOB at the network protocol level).

    - Fixed BUG#5022 - ResultSet should release Field[] instance in .close().

    - Fixed BUG#5069 -- ResultSet.getMetaData() should not return
      incorrectly-initialized metadata if the result set has been closed, but
      should instead throw a SQLException. Also fixed for getRow() and
      getWarnings() and traversal methods by calling checkClosed() before
      operating on instance-level fields that are nullified during .close().

    - Parse new timezone variables from 4.1.x servers.

    - Use _binary introducer for PreparedStatement.setBytes() and
      set*Stream() when connected to MySQL-4.1.x or newer to avoid
      misinterpretation during character conversion.

05-28-04 - Version 3.0.14-production

    - Fixed URL parsing error

05-27-04 - Version 3.0.13-production

    - Fixed BUG#3848 - Using a MySQLDatasource without server name fails

    - Fixed BUG#3920 - "No Database Selected" when using
    MysqlConnectionPoolDataSource.

    - Fixed BUG#3873 - PreparedStatement.getGeneratedKeys() method returns only
    1 result for batched insertions

05-18-04 - Version 3.0.12-production

    - Add unsigned attribute to DatabaseMetaData.getColumns() output
    in the TYPE_NAME column.

    - Added 'failOverReadOnly' property, to allow end-user to configure
    state of connection (read-only/writable) when failed over.

    - Backported 'change user' and 'reset server state' functionality
      from 3.1 branch, to allow clients of MysqlConnectionPoolDataSource
      to reset server state on getConnection() on a pooled connection.

    - Don't escape SJIS/GBK/BIG5 when using MySQL-4.1 or newer.

    - Allow 'url' parameter for MysqlDataSource and MysqlConnectionPool
      DataSource so that passing of other properties is possible from
      inside appservers.

    - Map duplicate key and foreign key errors to SQLState of
      '23000'.

    - Backport documentation tooling from 3.1 branch.

    - Return creating statement for ResultSets created by
      getGeneratedKeys() (BUG#2957)

    - Allow java.util.Date to be sent in as parameter to
      PreparedStatement.setObject(), converting it to a Timestamp
      to maintain full precision (BUG#3103).

    - Don't truncate BLOBs/CLOBs when using setBytes() and/or
      setBinary/CharacterStream() (BUG#2670).

    - Dynamically configure character set mappings for field-level
      character sets on MySQL-4.1.0 and newer using 'SHOW COLLATION'
      when connecting.

    - Map 'binary' character set to 'US-ASCII' to support DATETIME
      charset recognition for servers &gt;= 4.1.2

    - Use 'SET character_set_results" during initialization to allow any
      charset to be returned to the driver for result sets.

    - Use charsetnr returned during connect to encode queries before
      issuing 'SET NAMES' on MySQL &gt;= 4.1.0.

    - Add helper methods to ResultSetMetaData (getColumnCharacterEncoding()
      and getColumnCharacterSet()) to allow end-users to see what charset
      the driver thinks it should be using for the column.

    - Only set character_set_results for MySQL &gt;= 4.1.0.

    - Fixed BUG#3511, StringUtils.escapeSJISByteStream() not covering all
      eastern double-byte charsets correctly.

    - Renamed StringUtils.escapeSJISByteStream() to more appropriate
      escapeEasternUnicodeByteStream().

    - Fixed BUG#3554 - Not specifying database in URL caused MalformedURL
      exception.

    - Auto-convert MySQL encoding names to Java encoding names if used
      for characterEncoding property.

    - Added encoding names that are recognized on some JVMs to fix case
      where they were reverse-mapped to MySQL encoding names incorrectly.

    - Use junit.textui.TestRunner for all unit tests (to allow them to be
      run from the command line outside of Ant or Eclipse).

    - Fixed BUG#3557 - UpdatableResultSet not picking up default values
      for moveToInsertRow().

    - Fixed BUG#3570 - inconsistent reporting of column type. The server
      still doesn't return all types for *BLOBs *TEXT correctly, so the
      driver won't return those correctly.

    - Fixed BUG#3520 -- DBMD.getSQLStateType() returns incorrect value.

    - Fixed regression in PreparedStatement.setString() and eastern character
      encodings.

    - Made StringRegressionTest 4.1-unicode aware.

02-19-04 - Version 3.0.11-stable

    - Trigger a 'SET NAMES utf8' when encoding is forced to 'utf8' _or_
    'utf-8' via the 'characterEncoding' property. Previously, only the
    Java-style encoding name of 'utf-8' would trigger this.

    - AutoReconnect time was growing faster than exponentially (BUG#2447).

    - Fixed failover always going to last host in list (BUG#2578)

    - Added 'useUnbufferedInput' parameter, and now use it by default
      (due to JVM issue
      http://developer.java.sun.com/developer/bugParade/bugs/4401235.html)

    - Detect 'on/off' or '1','2','3' form of lower_case_table_names on
      server.

    - Return 'java.lang.Integer' for TINYINT and SMALLINT types from
      ResultSetMetaData.getColumnClassName() (fix for BUG#2852).

    - Return 'java.lang.Double' for FLOAT type from ResultSetMetaData.
      getColumnClassName() (fix for BUG#2855).

    - Return '[B' instead of java.lang.Object for BINARY, VARBINARY and
      LONGVARBINARY types from ResultSetMetaData.getColumnClassName()
      (JDBC compliance).

    - Issue connection events on all instances created from a
      ConnectionPoolDataSource.

01-13-04 - Version 3.0.10-stable

    - Don't count quoted id's when inside a 'string' in PreparedStatement
      parsing (fix for BUG#1511).

    - 'Friendlier' exception message for PacketTooLargeException
       (BUG#1534).

    - Backported fix for aliased tables and UpdatableResultSets in
      checkUpdatability() method from 3.1 branch.

    - Fix for ArrayIndexOutOfBounds exception when using Statement.setMaxRows()
      (BUG#1695).

    - Fixed BUG#1576, dealing with large blobs and split packets not being
      read correctly.

    - Fixed regression of Statement.getGeneratedKeys() and REPLACE statements.

    - Fixed BUG#1630, subsequent call to ResultSet.updateFoo() causes NPE if
      result set is not updatable.

    - Fix for 4.1.1-style auth with no password.

    - Fix for BUG#1731, Foreign Keys column sequence is not consistent in
      DatabaseMetaData.getImported/Exported/CrossReference().

    - Fix for BUG#1775 - DatabaseMetaData.getSystemFunction() returning
      bad function 'VResultsSion'.

    - Fix for BUG#1592 -- cross-database updatable result sets
      are not checked for updatability correctly.

    - DatabaseMetaData.getColumns() should return Types.LONGVARCHAR for
      MySQL LONGTEXT type.

    - ResultSet.getObject() on TINYINT and SMALLINT columns should return
      Java type 'Integer' (BUG#1913)

    - Added 'alwaysClearStream' connection property, which causes the driver
      to always empty any remaining data on the input stream before
      each query.

    - Added more descriptive error message 'Server Configuration Denies
      Access to DataSource', as well as retrieval of message from server.

    - Autoreconnect code didn't set catalog upon reconnect if it had been
      changed.

    - Implement ResultSet.updateClob().

    - ResultSetMetaData.isCaseSensitive() returned wrong value for CHAR/VARCHAR
      columns.

    - Fix for BUG#1933 -- Connection property "maxRows" not honored.

    - Fix for BUG#1925 -- Statements being created too many times in
      DBMD.extractForeignKeyFromCreateTable().

    - Fix for BUG#1914 -- Support escape sequence {fn convert ... }

    - Fix for BUG#1958 -- ArrayIndexOutOfBounds when parameter number ==
      number of parameters + 1.

    - Fix for BUG#2006 -- ResultSet.findColumn() should use first matching
      column name when there are duplicate column names in SELECT query
      (JDBC-compliance).

    - Removed static synchronization bottleneck from
      PreparedStatement.setTimestamp().

    - Removed static synchronization bottleneck from instance factory
      method of SingleByteCharsetConverter.

    - Enable caching of the parsing stage of prepared statements via
      the 'cachePrepStmts', 'prepStmtCacheSize' and 'prepStmtCacheSqlLimit'
      properties (disabled by default).

    - Speed up parsing of PreparedStatements, try to use one-pass whenever
      possible.

    - Fixed security exception when used in Applets (applets can't
      read the system property 'file.encoding' which is needed
      for LOAD DATA LOCAL INFILE).

    - Use constants for SQLStates.

    - Map charset 'ko18_ru' to 'ko18r' when connected to MySQL-4.1.0 or
      newer.

    - Ensure that Buffer.writeString() saves room for the \0.

    - Fixed exception 'Unknown character set 'danish' on connect w/ JDK-1.4.0

    - Fixed mappings in SQLError to report deadlocks with SQLStates of '41000'.

    - 'maxRows' property would affect internal statements, so check it for all
      statement creation internal to the driver, and set to 0 when it is not.

10-07-03 - Version 3.0.9-stable

    - Faster date handling code in ResultSet and PreparedStatement (no longer
      uses Date methods that synchronize on static calendars).

    - Fixed test for end of buffer in Buffer.readString().

    - Fixed ResultSet.previous() behavior to move current
      position to before result set when on first row
      of result set (bugs.mysql.com BUG#496)

    - Fixed Statement and PreparedStatement issuing bogus queries
      when setMaxRows() had been used and a LIMIT clause was present
      in the query.

    - Fixed BUG#661 - refreshRow didn't work when primary key values
      contained values that needed to be escaped (they ended up being
      doubly-escaped).

    - Support InnoDB contraint names when extracting foreign key info
      in DatabaseMetaData BUG#517 and BUG#664
      (impl. ideas from Parwinder Sekhon)

    - Backported 4.1 protocol changes from 3.1 branch (server-side SQL
      states, new field info, larger client capability flags,
      connect-with-database, etc).

    - Fix UpdatableResultSet to return values for getXXX() when on
      insert row (BUG#675).

    - The insertRow in an UpdatableResultSet is now loaded with
      the default column values when moveToInsertRow() is called
      (BUG#688)

    - DatabaseMetaData.getColumns() wasn't returning NULL for
      default values that are specified as NULL.

    - Change default statement type/concurrency to TYPE_FORWARD_ONLY
      and CONCUR_READ_ONLY (spec compliance).

    - Don't try and reset isolation level on reconnect if MySQL doesn't
      support them.

    - Don't wrap SQLExceptions in RowDataDynamic.

    - Don't change timestamp TZ twice if useTimezone==true (BUG#774)

    - Fixed regression in large split-packet handling (BUG#848).

    - Better diagnostic error messages in exceptions for 'streaming'
      result sets.

    - Issue exception on ResultSet.getXXX() on empty result set (wasn't
      caught in some cases).

    - Don't hide messages from exceptions thrown in I/O layers.

    - Don't fire connection closed events when closing pooled connections, or
      on PooledConnection.getConnection() with already open connections (BUG#884).

    - Clip +/- INF (to smallest and largest representative values for the type in
      MySQL) and NaN (to 0) for setDouble/setFloat(), and issue a warning on the
      statement when the server does not support +/- INF or NaN.

    - Fix for BUG#879, double-escaping of '\' when charset is SJIS or GBK and '\'
      appears in non-escaped input.

    - When emptying input stream of unused rows for 'streaming' result sets,
      have the current thread yield() every 100 rows in order to not monopolize
      CPU time.

    - Fixed BUG#1099, DatabaseMetaData.getColumns() getting confused about the
      keyword 'set' in character columns.

    - Fixed deadlock issue with Statement.setMaxRows().

    - Fixed CLOB.truncate(), BUG#1130

    - Optimized CLOB.setChracterStream(), BUG#1131

    - Made databaseName, portNumber and serverName optional parameters
      for MysqlDataSourceFactory (BUG#1246)

    - Fix for BUG#1247 -- ResultSet.get/setString mashing char 127

    - Backported auth. changes for 4.1.1 and newer from 3.1 branch.

    - Added com.mysql.jdbc.util.BaseBugReport to help creation of testcases
      for bug reports.

    - Added property to 'clobber' streaming results, by setting the
      'clobberStreamingResults' property to 'true' (the default is 'false').
      This will cause a 'streaming' ResultSet to be automatically
      closed, and any oustanding data still streaming from the server to
      be discarded if another query is executed before all the data has been
      read from the server.

05-23-03 - Version 3.0.8-stable

    - Allow bogus URLs in Driver.getPropertyInfo().

    - Return list of generated keys when using multi-value INSERTS
      with Statement.getGeneratedKeys().

    - Use JVM charset with filenames and 'LOAD DATA [LOCAL] INFILE'

    - Fix infinite loop with Connection.cleanup().

    - Changed Ant target 'compile-core' to 'compile-driver', and
      made testsuite compilation a separate target.

    - Fixed result set not getting set for Statement.executeUpdate(),
      which affected getGeneratedKeys() and getUpdateCount() in
      some cases.

    - Unicode character 0xFFFF in a string would cause the driver to
      throw an ArrayOutOfBoundsException (Bug #378)

    - Return correct amount of generated keys when using 'REPLACE'
      statements.

    - Fix problem detecting server character set in some cases.

    - Fix row data decoding error when using _very_ large packets.

    - Optimized row data decoding.

    - Issue exception when operating on an already-closed
      prepared statement.

    - Fixed SJIS encoding bug, thanks to Naoto Sato.

    - Optimized usage of EscapeProcessor.

    - Allow multiple calls to Statement.close()

04-08-03 - Version 3.0.7-stable

    - Fixed MysqlPooledConnection.close() calling wrong event type.

    - Fixed StringIndexOutOfBoundsException in PreparedStatement.
      setClob().

    - 4.1 Column Metadata fixes

    - Remove synchronization from Driver.connect() and
      Driver.acceptsUrl().

    - IOExceptions during a transaction now cause the Connection to
      be closed.

    - Fixed missing conversion for 'YEAR' type in ResultSetMetaData.
      getColumnTypeName().

    - Don't pick up indexes that start with 'pri' as primary keys
      for DBMD.getPrimaryKeys().

    - Throw SQLExceptions when trying to do operations on a forcefully
      closed Connection (i.e. when a communication link failure occurs).

    - You can now toggle profiling on/off using
      Connection.setProfileSql(boolean).

    - Fixed charset issues with database metadata (charset was not
      getting set correctly).

    - Updatable ResultSets can now be created for aliased tables/columns
      when connected to MySQL-4.1 or newer.

    - Fixed 'LOAD DATA LOCAL INFILE' bug when file &gt; max_allowed_packet.

    - Fixed escaping of 0x5c ('\') character for GBK and Big5 charsets.

    - Fixed ResultSet.getTimestamp() when underlying field is of type DATE.

    - Ensure that packet size from alignPacketSize() does not
      exceed MAX_ALLOWED_PACKET (JVM bug)

    - Don't reset Connection.isReadOnly() when autoReconnecting.

02-18-03 - Version 3.0.6-stable

    - Fixed ResultSetMetaData to return "" when catalog not known.
      Fixes NullPointerExceptions with Sun's CachedRowSet.

    - Fixed DBMD.getTypeInfo() and DBMD.getColumns() returning
      different value for precision in TEXT/BLOB types.

    - Allow ignoring of warning for 'non transactional tables' during
      rollback (compliance/usability) by setting 'ignoreNonTxTables'
      property to 'true'.

    - Fixed SQLExceptions getting swallowed on initial connect.

    - Fixed Statement.setMaxRows() to stop sending 'LIMIT' type queries
      when not needed (performance)

    - Clean up Statement query/method mismatch tests (i.e. INSERT not
      allowed with .executeQuery()).

    - More checks added in ResultSet traversal method to catch
      when in closed state.

    - Fixed ResultSetMetaData.isWritable() to return correct value.

    - Add 'window' of different NULL sorting behavior to
      DBMD.nullsAreSortedAtStart (4.0.2 to 4.0.10, true, otherwise,
      no).

    - Implemented Blob.setBytes(). You still need to pass the
      resultant Blob back into an updatable ResultSet or
      PreparedStatement to persist the changes, as MySQL does
      not support 'locators'.

    - Backported 4.1 charset field info changes from Connector/J 3.1

01-22-03 - Version 3.0.5-gamma

    - Fixed Buffer.fastSkipLenString() causing ArrayIndexOutOfBounds
      exceptions with some queries when unpacking fields.

    - Implemented an empty TypeMap for Connection.getTypeMap() so that
      some third-party apps work with MySQL (IBM WebSphere 5.0 Connection
      pool).

    - Added missing LONGTEXT type to DBMD.getColumns().

    - Retrieve TX_ISOLATION from database for
      Connection.getTransactionIsolation() when the MySQL version
      supports it, instead of an instance variable.

    - Quote table names in DatabaseMetaData.getColumns(),
      getPrimaryKeys(), getIndexInfo(), getBestRowIdentifier()

    - Greatly reduce memory required for setBinaryStream() in
      PreparedStatements.

    - Fixed ResultSet.isBeforeFirst() for empty result sets.

    - Added update options for foreign key metadata.


01-06-03 - Version 3.0.4-gamma

    - Added quoted identifiers to database names for
      Connection.setCatalog.

    - Added support for quoted identifiers in PreparedStatement
      parser.

    - Streamlined character conversion and byte[] handling in
      PreparedStatements for setByte().

    - Reduce memory footprint of PreparedStatements by sharing
      outbound packet with MysqlIO.

    - Added 'strictUpdates' property to allow control of amount
      of checking for 'correctness' of updatable result sets. Set this
      to 'false' if you want faster updatable result sets and you know
      that you create them from SELECTs on tables with primary keys and
      that you have selected all primary keys in your query.

    - Added support for 4.0.8-style large packets.

    - Fixed PreparedStatement.executeBatch() parameter overwriting.

12-17-02 - Version 3.0.3-dev

    - Changed charsToByte in SingleByteCharConverter to be non-static

    - Changed SingleByteCharConverter to use lazy initialization of each
      converter.

    - Fixed charset handling in Fields.java

    - Implemented Connection.nativeSQL()

    - More robust escape tokenizer -- recognize '--' comments, and allow
      nested escape sequences (see testsuite.EscapeProcessingTest)

    - DBMD.getImported/ExportedKeys() now handles multiple foreign keys
      per table.

    - Fixed ResultSetMetaData.getPrecision() returning incorrect values
      for some floating point types.

    - Fixed ResultSetMetaData.getColumnTypeName() returning BLOB for
      TEXT and TEXT for BLOB types.

    - Fixed Buffer.isLastDataPacket() for 4.1 and newer servers.

    - Added CLIENT_LONG_FLAG to be able to get more column flags
      (isAutoIncrement() being the most important)

    - Because of above, implemented ResultSetMetaData.isAutoIncrement()
      to use Field.isAutoIncrement().

    - Honor 'lower_case_table_names' when enabled in the server when
      doing table name comparisons in DatabaseMetaData methods.

    - Some MySQL-4.1 protocol support (extended field info from selects)

    - Use non-aliased table/column names and database names to fullly
      qualify tables and columns in UpdatableResultSet (requires
      MySQL-4.1 or newer)

    - Allow user to alter behavior of Statement/
      PreparedStatement.executeBatch() via 'continueBatchOnError' property
      (defaults to 'true').

    - Check for connection closed in more Connection methods
      (createStatement, prepareStatement, setTransactionIsolation,
      setAutoCommit).

    - More robust implementation of updatable result sets. Checks that
      _all_ primary keys of the table have been selected.

    - 'LOAD DATA LOCAL INFILE ...' now works, if your server is configured
      to allow it. Can be turned off with the 'allowLoadLocalInfile'
      property (see the README).

    - Substitute '?' for unknown character conversions in single-byte
      character sets instead of '\0'.

    - NamedPipeSocketFactory now works (only intended for Windows), see
      README for instructions.

11-08-02 - Version 3.0.2-dev

    - Fixed issue with updatable result sets and PreparedStatements not
      working

    - Fixed ResultSet.setFetchDirection(FETCH_UNKNOWN)

    - Fixed issue when calling Statement.setFetchSize() when using
      arbitrary values

    - Fixed incorrect conversion in ResultSet.getLong()

    - Implemented ResultSet.updateBlob().

    - Removed duplicate code from UpdatableResultSet (it can be inherited
      from ResultSet, the extra code for each method to handle updatability
      I thought might someday be necessary has not been needed).

    - Fixed "UnsupportedEncodingException" thrown when "forcing" a
      character encoding via properties.

    - Fixed various non-ASCII character encoding issues.

    - Added driver property 'useHostsInPrivileges'. Defaults to true.
      Affects whether or not '@hostname' will be used in
      DBMD.getColumn/TablePrivileges.

    - All DBMD result set columns describing schemas now return NULL
      to be more compliant with the behavior of other JDBC drivers
      for other databases (MySQL does not support schemas).

    - Added SSL support. See README for information on how to use it.

    - Properly restore connection properties when autoReconnecting
      or failing-over, including autoCommit state, and isolation level.

    - Use 'SHOW CREATE TABLE' when possible for determining foreign key
      information for DatabaseMetaData...also allows cascade options for
      DELETE information to be returned

    - Escape 0x5c character in strings for the SJIS charset.

    - Fixed start position off-by-1 error in Clob.getSubString()

    - Implemented Clob.truncate()

    - Implemented Clob.setString()

    - Implemented Clob.setAsciiStream()

    - Implemented Clob.setCharacterStream()

    - Added com.mysql.jdbc.MiniAdmin class, which allows you to send
      'shutdown' command to MySQL server...Intended to be used when 'embedding'
      Java and MySQL server together in an end-user application.

    - Added 'connectTimeout' parameter that allows users of JDK-1.4 and newer
      to specify a maxium time to wait to establish a connection.

    - Failover and autoReconnect only work when the connection is in a
      autoCommit(false) state, in order to stay transaction safe

    - Added 'queriesBeforeRetryMaster' property that specifies how many
      queries to issue when failed over before attempting to reconnect
      to the master (defaults to 50)

    - Fixed DBMD.supportsResultSetConcurrency() so that it returns true
      for ResultSet.TYPE_SCROLL_INSENSITIVE and ResultSet.CONCUR_READ_ONLY or
      ResultSet.CONCUR_UPDATABLE

    - Fixed ResultSet.isLast() for empty result sets (should return false).

    - PreparedStatement now honors stream lengths in setBinary/Ascii/Character
      Stream() unless you set the connection property
      'useStreamLengthsInPrepStmts' to 'false'.

    - Removed some not-needed temporary object creation by using Strings
      smarter in EscapeProcessor, Connection and DatabaseMetaData classes.

09-21-02 - Version 3.0.1-dev

    - Fixed ResultSet.getRow() off-by-one bug.

    - Fixed RowDataStatic.getAt() off-by-one bug.

    - Added limited Clob functionality (ResultSet.getClob(),
      PreparedStatemtent.setClob(),
      PreparedStatement.setObject(Clob).

    - Added socketTimeout parameter to URL.

    - Connection.isClosed() no longer "pings" the server.

    - Connection.close() issues rollback() when getAutoCommit() == false

    - Added "paranoid" parameter...sanitizes error messages removing
      "sensitive" information from them (i.e. hostnames, ports,
      usernames, etc.), as well as clearing "sensitive" data structures
      when possible.

    - Fixed ResultSetMetaData.isSigned() for TINYINT and BIGINT.

    - Charsets now automatically detected. Optimized code for single-byte
      character set conversion.

    - Implemented ResultSet.getCharacterStream()

    - Added "LOCAL TEMPORARY" to table types in DatabaseMetaData.getTableTypes()

    - Massive code clean-up to follow Java coding conventions (the time had come)


07-31-02 - Version 3.0.0-dev

    - !!! LICENSE CHANGE !!! The driver is now GPL. If you need
      non-GPL licenses, please contact me &lt;mark@mysql.com&gt;

    - JDBC-3.0 functionality including
      Statement/PreparedStatement.getGeneratedKeys() and
      ResultSet.getURL()

    - Performance enchancements - driver is now 50-100% faster
      in most situations, and creates fewer temporary objects

    - Repackaging...new driver name is "com.mysql.jdbc.Driver",
      old name still works, though (the driver is now provided
      by MySQL-AB)

    - Better checking for closed connections in Statement
      and PreparedStatement.

    - Support for streaming (row-by-row) result sets (see README)
      Thanks to Doron.

    - Support for large packets (new addition to MySQL-4.0 protocol),
      see README for more information.

    - JDBC Compliance -- Passes all tests besides stored procedure tests


    - Fix and sort primary key names in DBMetaData (SF bugs 582086 and 582086)

    - Float types now reported as java.sql.Types.FLOAT (SF bug 579573)

    - ResultSet.getTimestamp() now works for DATE types (SF bug 559134)

    - ResultSet.getDate/Time/Timestamp now recognizes all forms of invalid
      values that have been set to all zeroes by MySQL (SF bug 586058)

    - Testsuite now uses Junit (which you can get from www.junit.org)

    - The driver now only works with JDK-1.2 or newer.

    - Added multi-host failover support (see README)

    - General source-code cleanup.

    - Overall speed improvements via controlling transient object
      creation in MysqlIO class when reading packets

    - Performance improvements in  string handling and field
      metadata creation (lazily instantiated) contributed by
      Alex Twisleton-Wykeham-Fiennes


05-16-02 - Version 2.0.14

    - More code cleanup

    - PreparedStatement now releases resources on .close() (SF bug 553268)

    - Quoted identifiers not used if server version does not support them. Also,
      if server started with --ansi or --sql-mode=ANSI_QUOTES then '"' will be
      used as an identifier quote, otherwise '`' will be used.

    - ResultSet.getDouble() now uses code built into JDK to be more precise (but slower)

    - LogicalHandle.isClosed() calls through to physical connection

    - Added SQL profiling (to STDERR). Set "profileSql=true" in your JDBC url.
      See README for more information.

    - Fixed typo for relaxAutoCommit parameter.

04-24-02 - Version 2.0.13

    - More code cleanup.

    - Fixed unicode chars being read incorrectly (SF bug 541088)

    - Faster blob escaping for PrepStmt

    - Added set/getPortNumber() to DataSource(s) (SF bug 548167)

    - Added setURL() to MySQLXADataSource (SF bug 546019)

    - PreparedStatement.toString() fixed (SF bug 534026)

    - ResultSetMetaData.getColumnClassName() now implemented

    - Rudimentary version of Statement.getGeneratedKeys() from JDBC-3.0
      now implemented (you need to be using JDK-1.4 for this to work, I
      believe)

    - DBMetaData.getIndexInfo() - bad PAGES fixed (SF BUG 542201)

04-07-02 - Version 2.0.12

    - General code cleanup.

    - Added getIdleFor() method to Connection and MysqlLogicalHandle.

    - Relaxed synchronization in all classes, should fix 520615 and 520393.

    - Added getTable/ColumnPrivileges() to DBMD (fixes 484502).

    - Added new types to getTypeInfo(), fixed existing types thanks to
      Al Davis and Kid Kalanon.

    - Added support for BIT types (51870) to PreparedStatement.

    - Fixed getRow() bug (527165) in ResultSet

    - Fixes for ResultSet updatability in PreparedStatement.
    - Fixed timezone off by 1-hour bug in PreparedStatement (538286, 528785).

    - ResultSet: Fixed updatability (values being set to null
      if not updated).

    - DataSources - fixed setUrl bug (511614, 525565),
      wrong datasource class name (532816, 528767)

    - Added identifier quoting to all DatabaseMetaData methods
      that need them (should fix 518108)

    - Added support for YEAR type (533556)

    - ResultSet.insertRow() should now detect auto_increment fields
      in most cases and use that value in the new row. This detection
      will not work in multi-valued keys, however, due to the fact that
      the MySQL protocol does not return this information.

    - ResultSet.refreshRow() implemented.

    - Fixed testsuite.Traversal afterLast() bug, thanks to Igor Lastric.

01-27-02 - Version 2.0.11

    - Fixed missing DELETE_RULE value in
      DBMD.getImported/ExportedKeys() and getCrossReference().

    - Full synchronization of Statement.java.

    - More changes to fix "Unexpected end of input stream"
      errors when reading BLOBs. This should be the last fix.

01-24-02 - Version 2.0.10

     - Fixed spurious "Unexpected end of input stream" errors in
       MysqlIO (bug 507456).

     - Fixed null-pointer-exceptions when using
       MysqlConnectionPoolDataSource with Websphere 4 (bug 505839).

01-13-02 - Version 2.0.9

     - Ant build was corrupting included jar files, fixed
       (bug 487669).

     - Fixed extra memory allocation in MysqlIO.readPacket()
       (bug 488663).

     - Implementation of DatabaseMetaData.getExported/ImportedKeys() and
       getCrossReference().

     - Full synchronization on methods modifying instance and class-shared
       references, driver should be entirely thread-safe now (please
       let me know if you have problems)

     - DataSource implementations moved to org.gjt.mm.mysql.jdbc2.optional
       package, and (initial) implementations of PooledConnectionDataSource
       and XADataSource are in place (thanks to Todd Wolff for the
       implementation and testing of PooledConnectionDataSource with
       IBM WebSphere 4).

     - Added detection of network connection being closed when reading packets
       (thanks to Todd Lizambri).

     - Fixed quoting error with escape processor (bug 486265).

     - Report batch update support through DatabaseMetaData (bug 495101).

     - Fixed off-by-one-hour error in PreparedStatement.setTimestamp()
       (bug 491577).

     - Removed concatenation support from driver (the '||' operator),
       as older versions of VisualAge seem to be the only thing that
       use it, and it conflicts with the logical '||' operator. You will
       need to start mysqld with the "--ansi" flag to use the '||'
       operator as concatenation (bug 491680)

     - Fixed casting bug in PreparedStatement (bug 488663).

11-25-01 - Version 2.0.8

     - Batch updates now supported (thanks to some inspiration
       from Daniel Rall).

     - XADataSource/ConnectionPoolDataSource code (experimental)

     - PreparedStatement.setAnyNumericType() now handles positive
       exponents correctly (adds "+" so MySQL can understand it).

     - DatabaseMetaData.getPrimaryKeys() and getBestRowIdentifier()
       are now more robust in identifying primary keys (matches
       regardless of case or abbreviation/full spelling of Primary Key
       in Key_type column).

10-24-01 - Version 2.0.7

     - PreparedStatement.setCharacterStream() now implemented

     - Fixed dangling socket problem when in high availability
       (autoReconnect=true) mode, and finalizer for Connection will
       close any dangling sockets on GC.

     - Fixed ResultSetMetaData.getPrecision() returning one
       less than actual on newer versions of MySQL.

     - ResultSet.getBlob() now returns null if column value
       was null.

     - Character sets read from database if useUnicode=true
       and characterEncoding is not set. (thanks to
       Dmitry Vereshchagin)

     - Initial transaction isolation level read from
       database (if avaialable) (thanks to Dmitry Vereshchagin)

     - Fixed DatabaseMetaData.supportsTransactions(), and
       supportsTransactionIsolationLevel() and getTypeInfo()
       SQL_DATETIME_SUB and SQL_DATA_TYPE fields not being
       readable.

     - Fixed PreparedStatement generating SQL that would end
       up with syntax errors for some queries.

     - Fixed ResultSet.isAfterLast() always returning false.

     - Fixed timezone issue in PreparedStatement.setTimestamp()
       (thanks to Erik Olofsson)

     - Captialize type names when "captializeTypeNames=true"
       is passed in URL or properties (for WebObjects, thanks
       to Anjo Krank)

     - Updatable result sets now correctly handle NULL
       values in fields.

     - PreparedStatement.setDouble() now uses full-precision
       doubles (reverting a fix made earlier to truncate them).

     - PreparedStatement.setBoolean() will use 1/0 for values
       if your MySQL Version &gt;= 3.21.23.

06-16-01 - Version 2.0.6

     - Fixed PreparedStatement parameter checking

     - Fixed case-sensitive column names in ResultSet.java

06-13-01 - Version 2.0.5

     - Fixed ResultSet.getBlob() ArrayIndex out-of-bounds

     - Fixed ResultSetMetaData.getColumnTypeName for TEXT/BLOB

     - Fixed ArrayIndexOutOfBounds when sending large BLOB queries
       (Max size packet was not being set)

     - Added ISOLATION level support to Connection.setIsolationLevel()

     - Fixed NPE on PreparedStatement.executeUpdate() when all columns
       have not been set.

     - Fixed data parsing of TIMESTAMPs with 2-digit years

     - Added Byte to PreparedStatement.setObject()

     - ResultSet.getBoolean() now recognizes '-1' as 'true'

     - ResultSet has +/-Inf/inf support

     - ResultSet.insertRow() works now, even if not all columns are
       set (they will be set to "NULL")

     - DataBaseMetaData.getCrossReference() no longer ArrayIndexOOB

     - getObject() on ResultSet correctly does TINYINT-&gt;Byte and
       SMALLINT-&gt;Short

12-03-00 - Version 2.0.3

     - Implemented getBigDecimal() without scale component
       for JDBC2.

     - Fixed composite key problem with updateable result sets.

     - Added detection of -/+INF for doubles.

     - Faster ASCII string operations.

     - Fixed incorrect detection of MAX_ALLOWED_PACKET, so sending
       large blobs should work now.

     - Fixed off-by-one error in java.sql.Blob implementation code.

     - Added "ultraDevHack" URL parameter, set to "true" to allow
       (broken) Macromedia UltraDev to use the driver.

04-06-00 - Version 2.0.1

     - Fixed RSMD.isWritable() returning wrong value.
       Thanks to Moritz Maass.

     - Cleaned up exception handling when driver connects

     - Columns that are of type TEXT now return as Strings
       when you use getObject()

     - DatabaseMetaData.getPrimaryKeys() now works correctly wrt
       to key_seq. Thanks to Brian Slesinsky.

     - No escape processing is done on PreparedStatements anymore
       per JDBC spec.

     - Fixed many JDBC-2.0 traversal, positioning bugs, especially
       wrt to empty result sets. Thanks to Ron Smits, Nick Brook,
       Cessar Garcia and Carlos Martinez.

     - Fixed some issues with updatability support in ResultSet when
       using multiple primary keys.

02-21-00 - Version 2.0pre5

     - Fixed Bad Handshake problem.

01-10-00 - Version 2.0pre4

     - Fixes to ResultSet for insertRow() - Thanks to
       Cesar Garcia

     - Fix to Driver to recognize JDBC-2.0 by loading a JDBC-2.0
       class, instead of relying on JDK version numbers. Thanks
       to John Baker.

     - Fixed ResultSet to return correct row numbers

     - Statement.getUpdateCount() now returns rows matched,
       instead of rows actually updated, which is more SQL-92
       like.

10-29-99

     - Statement/PreparedStatement.getMoreResults() bug fixed.
       Thanks to Noel J. Bergman.

     - Added Short as a type to PreparedStatement.setObject().
       Thanks to Jeff Crowder

     - Driver now automagically configures maximum/preferred packet
       sizes by querying server.

     - Autoreconnect code uses fast ping command if server supports
       it.

     - Fixed various bugs wrt. to packet sizing when reading from
       the server and when alloc'ing to write to the server.

08-17-99 - Version 2.0pre

     - Now compiles under JDK-1.2. The driver supports both JDK-1.1
       and JDK-1.2 at the same time through a core set of classes.
       The driver will load the appropriate interface classes at
       runtime by figuring out which JVM version you are using.

     - Fixes for result sets with all nulls in the first row.
       (Pointed out by Tim Endres)

     - Fixes to column numbers in SQLExceptions in ResultSet
       (Thanks to Blas Rodriguez Somoza)

     - The database no longer needs to specified to connect.
       (Thanks to Christian Motschke)

07-04-99 - Version 1.2b

     - Better Documentation (in progress), in doc/mm.doc/book1.html

     - DBMD now allows null for a column name pattern (not in
       spec), which it changes to '%'.

     - DBMD now has correct types/lengths for getXXX().

     - ResultSet.getDate(), getTime(), and getTimestamp() fixes.
       (contributed by Alan Wilken)

     - EscapeProcessor now handles \{ \} and { or } inside quotes
       correctly. (thanks to Alik for some ideas on how to fix it)

     - Fixes to properties handling in Connection.
       (contributed by Juho Tikkala)

     - ResultSet.getObject() now returns null for NULL columns
       in the table, rather than bombing out.
       (thanks to Ben Grosman)

     - ResultSet.getObject() now returns Strings for types
       from MySQL that it doesn't know about. (Suggested by
       Chris Perdue)

     - Removed DataInput/Output streams, not needed, 1/2 number
       of method calls per IO operation.

     - Use default character encoding if one is not specified. This
       is a work-around for broken JVMs, because according to spec,
       EVERY JVM must support "ISO8859_1", but they don't.

     - Fixed Connection to use the platform character encoding
       instead of "ISO8859_1" if one isn't explicitly set. This
       fixes problems people were having loading the character-
       converter classes that didn't always exist (JVM bug).
       (thanks to Fritz Elfert for pointing out this problem)

     - Changed MysqlIO to re-use packets where possible to reduce
       memory usage.

     - Fixed escape-processor bugs pertaining to {} inside
       quotes.

04-14-99 - Version 1.2a

     - Fixed character-set support for non-Javasoft JVMs
       (thanks to many people for pointing it out)

     - Fixed ResultSet.getBoolean() to recognize 'y' &amp; 'n'
       as well as '1' &amp; '0' as boolean flags.
       (thanks to Tim Pizey)

     - Fixed ResultSet.getTimestamp() to give better performance.
       (thanks to Richard Swift)

     - Fixed getByte() for numeric types.
       (thanks to Ray Bellis)

     - Fixed DatabaseMetaData.getTypeInfo() for DATE type.
       (thanks to Paul Johnston)

     - Fixed EscapeProcessor for "fn" calls.
       (thanks to Piyush Shah at locomotive.org)

     - Fixed EscapeProcessor to not do extraneous work if there
       are no escape codes.
       (thanks to Ryan Gustafson)

     - Fixed Driver to parse URLs of the form "jdbc:mysql://host:port"
       (thanks to Richard Lobb)

03-24-99 - Version 1.1i

     - Fixed Timestamps for PreparedStatements

     - Fixed null pointer exceptions in RSMD and RS

     - Re-compiled with jikes for valid class files (thanks ms!)

03-08-99 - Version 1.1h

     - Fixed escape processor to deal with un-matched { and }
       (thanks to Craig Coles)

     - Fixed escape processor to create more portable (between
       DATETIME and TIMESTAMP types) representations so that
       it will work with BETWEEN clauses.
       (thanks to Craig Longman)

     - MysqlIO.quit() now closes the socket connection. Before,
       after many failed connections some OS's would run out
       of file descriptors. (thanks to Michael Brinkman)

     - Fixed NullPointerException in Driver.getPropertyInfo.
       (thanks to Dave Potts)

     - Fixes to MysqlDefs to allow all *text fields to be
       retrieved as Strings.
       (thanks to Chris at Leverage)

     - Fixed setDouble in PreparedStatement for large numbers
       to avoid sending scientific notation to the database.
       (thanks to J.S. Ferguson)

     - Fixed getScale() and getPrecision() in RSMD.
       (contrib'd by James Klicman)

     - Fixed getObject() when field was DECIMAL or NUMERIC
       (thanks to Bert Hobbs)

     - DBMD.getTables() bombed when passed a null table-name
       pattern. Fixed. (thanks to Richard Lobb)

     - Added check for "client not authorized" errors during
       connect. (thanks to Hannes Wallnoefer)

02-19-99 - Version 1.1g

     - Result set rows are now byte arrays. Blobs and Unicode
       work bidriectonally now. The useUnicode and encoding
       options are implemented now.

     - Fixes to PreparedStatement to send binary set by
       setXXXStream to be sent un-touched to the MySQL server.

     - Fixes to getDriverPropertyInfo().

12-31-98 - Version 1.1f

     - Changed all ResultSet fields to Strings, this should allow
       Unicode to work, but your JVM must be able to convert
       between the character sets. This should also make reading
       data from the server be a bit quicker, because there is now
       no conversion from StringBuffer to String.

     - Changed PreparedStatement.streamToString() to be more
       efficient (code from Uwe Schaefer).

     - URL parsing is more robust (throws SQL exceptions on errors
       rather than NullPointerExceptions)

     - PreparedStatement now can convert Strings to Time/Date values
       via setObject() (code from Robert Currey).

     - IO no longer hangs in Buffer.readInt(), that bug was
       introduced in 1.1d when changing to all byte-arrays for
       result sets. (Pointed out by Samo Login)

11-03-98 - Version 1.1b

     - Fixes to DatabaseMetaData to allow both IBM VA and J-Builder
       to work. Let me know how it goes. (thanks to Jac Kersing)

     - Fix to ResultSet.getBoolean() for NULL strings
       (thanks to Barry Lagerweij)

     - Beginning of code cleanup, and formatting. Getting ready
       to branch this off to a parallel JDBC-2.0 source tree.

     - Added "final" modifier to critical sections in MysqlIO and
       Buffer to allow compiler to inline methods for speed.

9-29-98

     - If object references passed to setXXX() in PreparedStatement are
       null, setNull() is automatically called for you. (Thanks for the
       suggestion goes to Erik Ostrom)

     - setObject() in PreparedStatement will now attempt to write a
       serialized  representation of the object to the database for
       objects of Types.OTHER and objects of unknown type.

     - Util now has a static method readObject() which given a ResultSet
       and a column index will re-instantiate an object serialized in
       the above manner.

9-02-98 - Vesion 1.1

     - Got rid of "ugly hack" in MysqlIO.nextRow(). Rather than
       catch an exception, Buffer.isLastDataPacket() was fixed.

     - Connection.getCatalog() and Connection.setCatalog()
       should work now.

     - Statement.setMaxRows() works, as well as setting
       by property maxRows. Statement.setMaxRows() overrides
       maxRows set via properties or url parameters.

     - Automatic re-connection is available. Because it has
       to "ping" the database before each query, it is
       turned off by default. To use it, pass in "autoReconnect=true"
       in the connection URL. You may also change the number of
       reconnect tries, and the initial timeout value via
       "maxReconnects=n" (default 3) and "initialTimeout=n"
       (seconds, default 2) parameters. The timeout is an
       exponential backoff type of timeout, e.g. if you have initial
       timeout of 2 seconds, and maxReconnects of 3, then the driver
       will timeout 2 seconds, 4 seconds, then 16 seconds between each
       re-connection attempt.

8-24-98 - Version 1.0

     - Fixed handling of blob data in Buffer.java

     - Fixed bug with authentication packet being
       sized too small.

     - The JDBC Driver is now under the LPGL

8-14-98 -

     - Fixed Buffer.readLenString() to correctly
          read data for BLOBS.

     - Fixed PreparedStatement.stringToStream to
          correctly read data for BLOBS.

     - Fixed PreparedStatement.setDate() to not
       add a day.
       (above fixes thanks to Vincent Partington)

     - Added URL parameter parsing (?user=... etc).


8-04-98 - Version 0.9d

     - Big news! New package name. Tim Endres from ICE
       Engineering is starting a new source tree for
       GNU GPL'd Java software. He's graciously given
       me the org.gjt.mm package directory to use, so now
       the driver is in the org.gjt.mm.mysql package scheme.
       I'm "legal" now. Look for more information on Tim's
       project soon.

     - Now using dynamically sized packets to reduce
       memory usage when sending commands to the DB.

     - Small fixes to getTypeInfo() for parameters, etc.

     - DatabaseMetaData is now fully implemented. Let me
       know if these drivers work with the various IDEs
       out there. I've heard that they're working with
       JBuilder right now.

     - Added JavaDoc documentation to the package.

     - Package now available in .zip or .tar.gz.

7-28-98 - Version 0.9

     - Implemented getTypeInfo().
       Connection.rollback() now throws an SQLException
       per the JDBC spec.

     - Added PreparedStatement that supports all JDBC API
       methods for PreparedStatement including InputStreams.
       Please check this out and let me know if anything is
       broken.

     - Fixed a bug in ResultSet that would break some
       queries that only returned 1 row.

     - Fixed bugs in DatabaseMetaData.getTables(),
       DatabaseMetaData.getColumns() and
       DatabaseMetaData.getCatalogs().

     - Added functionality to Statement that allows
       executeUpdate() to store values for IDs that are
       automatically generated for AUTO_INCREMENT fields.
       Basically, after an executeUpdate(), look at the
       SQLWarnings for warnings like "LAST_INSERTED_ID =
       'some number', COMMAND = 'your SQL query'".

       If you are using AUTO_INCREMENT fields in your
       tables and are executing a lot of executeUpdate()s
       on one Statement, be sure to clearWarnings() every
       so often to save memory.

7-06-98 - Version 0.8

     - Split MysqlIO and Buffer to separate classes. Some
       ClassLoaders gave an IllegalAccess error for some
       fields in those two classes. Now mm.mysql works in
       applets and all classloaders.

       Thanks to Joe Ennis &lt;jce@mail.boone.com&gt; for pointing
       out the problem and working on a fix with me.

7-01-98 - Version 0.7

     - Fixed DatabaseMetadata problems in getColumns() and
       bug in switch statement in the Field constructor.

       Thanks to Costin Manolache &lt;costin@tdiinc.com&gt; for
       pointing these out.

5-21-98 - Version 0.6

     - Incorporated efficiency changes from
       Richard Swift &lt;Richard.Swift@kanatek.ca&gt; in
       MysqlIO.java and ResultSet.java

     - We're now 15% faster than gwe's driver.

     - Started working on DatabaseMetaData.

       The following methods are implemented:
        * getTables()
        * getTableTypes()
        * getColumns
        * getCatalogs()
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